From 3c9ec94e82c8ff626e3e447b6257be564cc5195d Mon Sep 17 00:00:00 2001
From: Victor XField <vxfield@outlook.com>
Date: Tue, 24 Nov 2020 11:57:10 -0800
Subject: [PATCH 01/17] Initial attempt to detect .NET SDK 3.1 and display a
 message if not found

(cherry picked from commit 59681e9219a94ca5aaeed118b3b9e5e79e33456e)
---
 .../LanguageServer/LanguageServer.cs          | 19 ++++++++++
 src/QsCompiler/LanguageServer/Program.cs      |  1 +
 src/QsCompiler/LanguageServer/Utils.cs        | 35 +++++++++++++++++++
 3 files changed, 55 insertions(+)

diff --git a/src/QsCompiler/LanguageServer/LanguageServer.cs b/src/QsCompiler/LanguageServer/LanguageServer.cs
index ccb10ad6c3..fe32e94935 100644
--- a/src/QsCompiler/LanguageServer/LanguageServer.cs
+++ b/src/QsCompiler/LanguageServer/LanguageServer.cs
@@ -126,6 +126,25 @@ internal Task NotifyClientAsync(string method, object args) =>
         internal Task PublishDiagnosticsAsync(PublishDiagnosticParams diagnostics) =>
             this.NotifyClientAsync(Methods.TextDocumentPublishDiagnosticsName, diagnostics);
 
+        internal void CheckDotNetSDKVersion()
+        {
+            var sdkVersions = DotNetSDKHelper.GetSDKVersions();
+            if (sdkVersions == null)
+            {
+                this.LogToWindow($"Unable to detect .NET SDK versions", MessageType.Error);
+            }
+            else
+            {
+                if (!sdkVersions.HasDotNet31)
+                {
+                    this.LogToWindow($".NET SDK 3.1 not found. QDK requires .NET SDK 3.1 to work properly.", MessageType.Error);
+                    this.ShowInWindow(
+                        $"QDK requires .NET SDK 3.1 to work properly. Please install .NET SDK 3.1 from https://dotnet.microsoft.com/download/dotnet-core/3.1",
+                        MessageType.Error);
+                }
+            }
+        }
+
         /// <summary>
         /// does not actually do anything unless the corresponding flag is defined upon compilation
         /// </summary>
diff --git a/src/QsCompiler/LanguageServer/Program.cs b/src/QsCompiler/LanguageServer/Program.cs
index a389d29e6f..50407cf34f 100644
--- a/src/QsCompiler/LanguageServer/Program.cs
+++ b/src/QsCompiler/LanguageServer/Program.cs
@@ -140,6 +140,7 @@ private static int Run(Options options)
             Log("Listening...", options.LogFile);
             try
             {
+                server.CheckDotNetSDKVersion();
                 server.WaitForShutdown();
             }
             catch (Exception ex)
diff --git a/src/QsCompiler/LanguageServer/Utils.cs b/src/QsCompiler/LanguageServer/Utils.cs
index f7c5425d77..1139f27c4f 100644
--- a/src/QsCompiler/LanguageServer/Utils.cs
+++ b/src/QsCompiler/LanguageServer/Utils.cs
@@ -4,6 +4,8 @@
 using System;
 using System.Collections.Generic;
 using System.Collections.Immutable;
+using System.Diagnostics;
+using System.Text.RegularExpressions;
 using Microsoft.Build.Framework;
 using Microsoft.Build.Utilities;
 using Microsoft.Quantum.QsCompiler;
@@ -123,4 +125,37 @@ public override void Initialize(IEventSource eventSource)
             }
         }
     }
+
+    internal static class DotNetSDKHelper
+    {
+        private static readonly Regex DotNet31Regex = new Regex(@"^3\.1\.\d+", RegexOptions.Multiline | RegexOptions.Compiled);
+        private static readonly Regex DotNet50Regex = new Regex(@"^5\.0\.\d+", RegexOptions.Multiline | RegexOptions.Compiled);
+
+        public class DotNetSDKVersions
+        {
+            public bool HasDotNet50 { get; set; }
+            public bool HasDotNet31 { get; set; }
+        }
+
+        public static DotNetSDKVersions? GetSDKVersions()
+        {
+            var listSdkProcess = Process.Start(
+                new ProcessStartInfo()
+                {
+                    FileName = "dotnet",
+                    Arguments = "--list-sdks",
+                    RedirectStandardOutput = true,
+                });
+            if (listSdkProcess.WaitForExit(3000))
+            {
+                var sdks = listSdkProcess.StandardOutput.ReadToEnd();
+                return new DotNetSDKVersions()
+                {
+                    HasDotNet31 = DotNet31Regex.IsMatch(sdks),
+                    HasDotNet50 = DotNet50Regex.IsMatch(sdks),
+                };
+            }
+            return null;
+        }
+    }
 }

From 16622dc0196edb3432fe415c2e4868f6df7c0bd6 Mon Sep 17 00:00:00 2001
From: Victor XField <vxfield@outlook.com>
Date: Tue, 24 Nov 2020 14:20:22 -0800
Subject: [PATCH 02/17] Show a dialog with option to open .NET 3.1 download
 page

(cherry picked from commit b538b3dd507a71f077bd132d087091f123df4039)
---
 .../LanguageServer/LanguageServer.cs          | 29 +++++++++++++++----
 src/QsCompiler/LanguageServer/Program.cs      |  2 +-
 src/QsCompiler/LanguageServer/Utils.cs        | 27 +++++++++++++++--
 3 files changed, 49 insertions(+), 9 deletions(-)

diff --git a/src/QsCompiler/LanguageServer/LanguageServer.cs b/src/QsCompiler/LanguageServer/LanguageServer.cs
index fe32e94935..22f63992e4 100644
--- a/src/QsCompiler/LanguageServer/LanguageServer.cs
+++ b/src/QsCompiler/LanguageServer/LanguageServer.cs
@@ -4,6 +4,7 @@
 using System;
 using System.Collections.Generic;
 using System.Collections.Immutable;
+using System.Diagnostics;
 using System.IO;
 using System.Linq;
 using System.Reactive.Linq;
@@ -123,12 +124,15 @@ public void Dispose()
         internal Task NotifyClientAsync(string method, object args) =>
             this.rpc.NotifyWithParameterObjectAsync(method, args);  // no need to wait for completion
 
+        internal Task<T> InvokeAsync<T>(string method, object args) =>
+            this.rpc.InvokeWithParameterObjectAsync<T>(method, args);
+
         internal Task PublishDiagnosticsAsync(PublishDiagnosticParams diagnostics) =>
             this.NotifyClientAsync(Methods.TextDocumentPublishDiagnosticsName, diagnostics);
 
-        internal void CheckDotNetSDKVersion()
+        internal async void CheckDotNetSdkVersion()
         {
-            var sdkVersions = DotNetSDKHelper.GetSDKVersions();
+            var sdkVersions = DotNetSdkHelper.GetSdkVersions();
             if (sdkVersions == null)
             {
                 this.LogToWindow($"Unable to detect .NET SDK versions", MessageType.Error);
@@ -137,10 +141,23 @@ internal void CheckDotNetSDKVersion()
             {
                 if (!sdkVersions.HasDotNet31)
                 {
-                    this.LogToWindow($".NET SDK 3.1 not found. QDK requires .NET SDK 3.1 to work properly.", MessageType.Error);
-                    this.ShowInWindow(
-                        $"QDK requires .NET SDK 3.1 to work properly. Please install .NET SDK 3.1 from https://dotnet.microsoft.com/download/dotnet-core/3.1",
-                        MessageType.Error);
+                    const string dotnet31Url = "https://dotnet.microsoft.com/download/dotnet-core/3.1";
+                    this.LogToWindow($".NET SDK 3.1 not found. The Quantum Development Kit Extension requires .NET SDK 3.1 to work properly ({dotnet31Url}).", MessageType.Error);
+                    var downloadAction = new MessageActionItem { Title = "Download" };
+                    var cancelAction = new MessageActionItem { Title = "No, thanks" };
+                    var selectedAction = await this.ShowDialogInWindowAsync(
+                        $"The Quantum Development Kit Extension requires .NET SDK 3.1 to work properly. Please install .NET SDK 3.1.",
+                        MessageType.Error,
+                        new[] { downloadAction, cancelAction });
+                    if (selectedAction != null
+                        && selectedAction.Title == downloadAction.Title)
+                    {
+                        Process.Start(new ProcessStartInfo
+                        {
+                            FileName = dotnet31Url,
+                            UseShellExecute = true
+                        });
+                    }
                 }
             }
         }
diff --git a/src/QsCompiler/LanguageServer/Program.cs b/src/QsCompiler/LanguageServer/Program.cs
index 50407cf34f..16f4e4cbbf 100644
--- a/src/QsCompiler/LanguageServer/Program.cs
+++ b/src/QsCompiler/LanguageServer/Program.cs
@@ -140,7 +140,7 @@ private static int Run(Options options)
             Log("Listening...", options.LogFile);
             try
             {
-                server.CheckDotNetSDKVersion();
+                server.CheckDotNetSdkVersion();
                 server.WaitForShutdown();
             }
             catch (Exception ex)
diff --git a/src/QsCompiler/LanguageServer/Utils.cs b/src/QsCompiler/LanguageServer/Utils.cs
index 1139f27c4f..2bc352f90b 100644
--- a/src/QsCompiler/LanguageServer/Utils.cs
+++ b/src/QsCompiler/LanguageServer/Utils.cs
@@ -6,6 +6,7 @@
 using System.Collections.Immutable;
 using System.Diagnostics;
 using System.Text.RegularExpressions;
+using System.Threading.Tasks;
 using Microsoft.Build.Framework;
 using Microsoft.Build.Utilities;
 using Microsoft.Quantum.QsCompiler;
@@ -35,6 +36,23 @@ internal static void ShowInWindow(this QsLanguageServer server, string text, Mes
             _ = server.NotifyClientAsync(Methods.WindowShowMessageName, message);
         }
 
+        /// <summary>
+        /// Shows a dialog window with options (actions) to the user, and returns the selected option (action).
+        /// </summary>
+        internal static async Task<MessageActionItem> ShowDialogInWindowAsync(this QsLanguageServer server, string text, MessageType severity, MessageActionItem[] actionItems)
+        {
+            var message =
+                new ShowMessageRequestParams()
+                {
+                    Message = text,
+                    MessageType = severity,
+                    Actions = actionItems
+                };
+            QsCompilerError.Verify(server != null && message != null, "cannot show message - given server or text was null");
+            var action = await server.InvokeAsync<MessageActionItem>(Methods.WindowShowMessageRequestName, message);
+            return action;
+        }
+
         /// <summary>
         /// Logs the given text in the editor.
         /// </summary>
@@ -126,7 +144,7 @@ public override void Initialize(IEventSource eventSource)
         }
     }
 
-    internal static class DotNetSDKHelper
+    internal static class DotNetSdkHelper
     {
         private static readonly Regex DotNet31Regex = new Regex(@"^3\.1\.\d+", RegexOptions.Multiline | RegexOptions.Compiled);
         private static readonly Regex DotNet50Regex = new Regex(@"^5\.0\.\d+", RegexOptions.Multiline | RegexOptions.Compiled);
@@ -134,10 +152,11 @@ internal static class DotNetSDKHelper
         public class DotNetSDKVersions
         {
             public bool HasDotNet50 { get; set; }
+
             public bool HasDotNet31 { get; set; }
         }
 
-        public static DotNetSDKVersions? GetSDKVersions()
+        public static DotNetSDKVersions? GetSdkVersions()
         {
             var listSdkProcess = Process.Start(
                 new ProcessStartInfo()
@@ -148,6 +167,10 @@ public class DotNetSDKVersions
                 });
             if (listSdkProcess.WaitForExit(3000))
             {
+                if (listSdkProcess.ExitCode != 0)
+                {
+                    return null;
+                }
                 var sdks = listSdkProcess.StandardOutput.ReadToEnd();
                 return new DotNetSDKVersions()
                 {

From f992fca79ff4029dd32e4aa233ffd9b903bdfcc4 Mon Sep 17 00:00:00 2001
From: Victor XField <vxfield@outlook.com>
Date: Tue, 24 Nov 2020 14:22:12 -0800
Subject: [PATCH 03/17] Better error message

(cherry picked from commit 28e79dd23260af8422d0a9080cb31f0978e05fcf)
---
 src/QsCompiler/LanguageServer/LanguageServer.cs | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/QsCompiler/LanguageServer/LanguageServer.cs b/src/QsCompiler/LanguageServer/LanguageServer.cs
index 22f63992e4..379732dac2 100644
--- a/src/QsCompiler/LanguageServer/LanguageServer.cs
+++ b/src/QsCompiler/LanguageServer/LanguageServer.cs
@@ -142,11 +142,11 @@ internal async void CheckDotNetSdkVersion()
                 if (!sdkVersions.HasDotNet31)
                 {
                     const string dotnet31Url = "https://dotnet.microsoft.com/download/dotnet-core/3.1";
-                    this.LogToWindow($".NET SDK 3.1 not found. The Quantum Development Kit Extension requires .NET SDK 3.1 to work properly ({dotnet31Url}).", MessageType.Error);
+                    this.LogToWindow($".NET SDK 3.1 not found. Quantum Development Kit Extension requires .NET Core SDK 3.1 to work properly ({dotnet31Url}).", MessageType.Error);
                     var downloadAction = new MessageActionItem { Title = "Download" };
                     var cancelAction = new MessageActionItem { Title = "No, thanks" };
                     var selectedAction = await this.ShowDialogInWindowAsync(
-                        $"The Quantum Development Kit Extension requires .NET SDK 3.1 to work properly. Please install .NET SDK 3.1.",
+                        $"Quantum Development Kit Extension requires .NET Core SDK 3.1 to work properly. Please install .NET SDK 3.1.",
                         MessageType.Error,
                         new[] { downloadAction, cancelAction });
                     if (selectedAction != null

From 1373031c436e5dd0e49d2d0a45548df4ed06e052 Mon Sep 17 00:00:00 2001
From: XField <58103249+vxfield@users.noreply.github.com>
Date: Tue, 24 Nov 2020 15:45:07 -0800
Subject: [PATCH 04/17] Update src/QsCompiler/LanguageServer/Utils.cs

Co-authored-by: Sarah Marshall <33814365+samarsha@users.noreply.github.com>
(cherry picked from commit f2cd93bee2e1fb033cdc9ce13b6c8e0751b27dac)
---
 src/QsCompiler/LanguageServer/Utils.cs | 1 -
 1 file changed, 1 deletion(-)

diff --git a/src/QsCompiler/LanguageServer/Utils.cs b/src/QsCompiler/LanguageServer/Utils.cs
index 2bc352f90b..1bf1acad5b 100644
--- a/src/QsCompiler/LanguageServer/Utils.cs
+++ b/src/QsCompiler/LanguageServer/Utils.cs
@@ -48,7 +48,6 @@ internal static async Task<MessageActionItem> ShowDialogInWindowAsync(this QsLan
                     MessageType = severity,
                     Actions = actionItems
                 };
-            QsCompilerError.Verify(server != null && message != null, "cannot show message - given server or text was null");
             var action = await server.InvokeAsync<MessageActionItem>(Methods.WindowShowMessageRequestName, message);
             return action;
         }

From 8f9de2aa86197a3f240811120febe668a1ffb38c Mon Sep 17 00:00:00 2001
From: XField <58103249+vxfield@users.noreply.github.com>
Date: Tue, 24 Nov 2020 15:45:23 -0800
Subject: [PATCH 05/17] Update src/QsCompiler/LanguageServer/Utils.cs

Co-authored-by: Sarah Marshall <33814365+samarsha@users.noreply.github.com>
(cherry picked from commit de463e00ac8d0011a6405b58c6df61ddccd79c4d)
---
 src/QsCompiler/LanguageServer/Utils.cs | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/src/QsCompiler/LanguageServer/Utils.cs b/src/QsCompiler/LanguageServer/Utils.cs
index 1bf1acad5b..2b5e920da7 100644
--- a/src/QsCompiler/LanguageServer/Utils.cs
+++ b/src/QsCompiler/LanguageServer/Utils.cs
@@ -48,8 +48,7 @@ internal static async Task<MessageActionItem> ShowDialogInWindowAsync(this QsLan
                     MessageType = severity,
                     Actions = actionItems
                 };
-            var action = await server.InvokeAsync<MessageActionItem>(Methods.WindowShowMessageRequestName, message);
-            return action;
+            return await server.InvokeAsync<MessageActionItem>(Methods.WindowShowMessageRequestName, message);
         }
 
         /// <summary>

From aeb8972b6ef3a27a4ac671c126eda822af692420 Mon Sep 17 00:00:00 2001
From: XField <58103249+vxfield@users.noreply.github.com>
Date: Tue, 24 Nov 2020 15:46:00 -0800
Subject: [PATCH 06/17] Update src/QsCompiler/LanguageServer/LanguageServer.cs

Co-authored-by: Sarah Marshall <33814365+samarsha@users.noreply.github.com>
(cherry picked from commit 7911bd54ec92ba4fd767e18da69511289c037236)
---
 src/QsCompiler/LanguageServer/LanguageServer.cs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/QsCompiler/LanguageServer/LanguageServer.cs b/src/QsCompiler/LanguageServer/LanguageServer.cs
index 379732dac2..7dafa60be5 100644
--- a/src/QsCompiler/LanguageServer/LanguageServer.cs
+++ b/src/QsCompiler/LanguageServer/LanguageServer.cs
@@ -135,7 +135,7 @@ internal async void CheckDotNetSdkVersion()
             var sdkVersions = DotNetSdkHelper.GetSdkVersions();
             if (sdkVersions == null)
             {
-                this.LogToWindow($"Unable to detect .NET SDK versions", MessageType.Error);
+                this.LogToWindow("Unable to detect .NET SDK versions", MessageType.Error);
             }
             else
             {

From aafbb3d3e141ccacf611548c07d18912552c45bd Mon Sep 17 00:00:00 2001
From: XField <58103249+vxfield@users.noreply.github.com>
Date: Tue, 24 Nov 2020 15:46:15 -0800
Subject: [PATCH 07/17] Update src/QsCompiler/LanguageServer/LanguageServer.cs

Co-authored-by: Sarah Marshall <33814365+samarsha@users.noreply.github.com>
(cherry picked from commit c19177d5c85697f8957910b26e9e03bdf00645d5)
---
 src/QsCompiler/LanguageServer/LanguageServer.cs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/QsCompiler/LanguageServer/LanguageServer.cs b/src/QsCompiler/LanguageServer/LanguageServer.cs
index 7dafa60be5..1af9bf0264 100644
--- a/src/QsCompiler/LanguageServer/LanguageServer.cs
+++ b/src/QsCompiler/LanguageServer/LanguageServer.cs
@@ -146,7 +146,7 @@ internal async void CheckDotNetSdkVersion()
                     var downloadAction = new MessageActionItem { Title = "Download" };
                     var cancelAction = new MessageActionItem { Title = "No, thanks" };
                     var selectedAction = await this.ShowDialogInWindowAsync(
-                        $"Quantum Development Kit Extension requires .NET Core SDK 3.1 to work properly. Please install .NET SDK 3.1.",
+                        "Quantum Development Kit Extension requires .NET Core SDK 3.1 to work properly. Please install .NET SDK 3.1.",
                         MessageType.Error,
                         new[] { downloadAction, cancelAction });
                     if (selectedAction != null

From 140d10d0b5871e0a6854b6b93d73a5fd37ff28d6 Mon Sep 17 00:00:00 2001
From: Victor XField <vxfield@outlook.com>
Date: Tue, 24 Nov 2020 16:15:19 -0800
Subject: [PATCH 08/17] Addressing minor PR review comments

(cherry picked from commit 283cecdf4c74f6d3e5ef65b015c305a4dd10d070)
---
 src/QsCompiler/LanguageServer/LanguageServer.cs | 10 +++++-----
 src/QsCompiler/LanguageServer/Utils.cs          | 16 ++--------------
 2 files changed, 7 insertions(+), 19 deletions(-)

diff --git a/src/QsCompiler/LanguageServer/LanguageServer.cs b/src/QsCompiler/LanguageServer/LanguageServer.cs
index 1af9bf0264..8d708aa89b 100644
--- a/src/QsCompiler/LanguageServer/LanguageServer.cs
+++ b/src/QsCompiler/LanguageServer/LanguageServer.cs
@@ -132,21 +132,21 @@ internal Task PublishDiagnosticsAsync(PublishDiagnosticParams diagnostics) =>
 
         internal async void CheckDotNetSdkVersion()
         {
-            var sdkVersions = DotNetSdkHelper.GetSdkVersions();
-            if (sdkVersions == null)
+            var isDotNet31Installed = DotNetSdkHelper.IsDotNet31Installed();
+            if (isDotNet31Installed == null)
             {
                 this.LogToWindow("Unable to detect .NET SDK versions", MessageType.Error);
             }
             else
             {
-                if (!sdkVersions.HasDotNet31)
+                if (isDotNet31Installed != true)
                 {
                     const string dotnet31Url = "https://dotnet.microsoft.com/download/dotnet-core/3.1";
-                    this.LogToWindow($".NET SDK 3.1 not found. Quantum Development Kit Extension requires .NET Core SDK 3.1 to work properly ({dotnet31Url}).", MessageType.Error);
+                    this.LogToWindow($".NET Core SDK 3.1 not found. Quantum Development Kit Extension requires .NET Core SDK 3.1 to work properly ({dotnet31Url}).", MessageType.Error);
                     var downloadAction = new MessageActionItem { Title = "Download" };
                     var cancelAction = new MessageActionItem { Title = "No, thanks" };
                     var selectedAction = await this.ShowDialogInWindowAsync(
-                        "Quantum Development Kit Extension requires .NET Core SDK 3.1 to work properly. Please install .NET SDK 3.1.",
+                        "Quantum Development Kit Extension requires .NET Core SDK 3.1 to work properly. Please install .NET Core SDK 3.1.",
                         MessageType.Error,
                         new[] { downloadAction, cancelAction });
                     if (selectedAction != null
diff --git a/src/QsCompiler/LanguageServer/Utils.cs b/src/QsCompiler/LanguageServer/Utils.cs
index 2b5e920da7..516032ab03 100644
--- a/src/QsCompiler/LanguageServer/Utils.cs
+++ b/src/QsCompiler/LanguageServer/Utils.cs
@@ -145,16 +145,8 @@ public override void Initialize(IEventSource eventSource)
     internal static class DotNetSdkHelper
     {
         private static readonly Regex DotNet31Regex = new Regex(@"^3\.1\.\d+", RegexOptions.Multiline | RegexOptions.Compiled);
-        private static readonly Regex DotNet50Regex = new Regex(@"^5\.0\.\d+", RegexOptions.Multiline | RegexOptions.Compiled);
 
-        public class DotNetSDKVersions
-        {
-            public bool HasDotNet50 { get; set; }
-
-            public bool HasDotNet31 { get; set; }
-        }
-
-        public static DotNetSDKVersions? GetSdkVersions()
+        public static bool? IsDotNet31Installed()
         {
             var listSdkProcess = Process.Start(
                 new ProcessStartInfo()
@@ -170,11 +162,7 @@ public class DotNetSDKVersions
                     return null;
                 }
                 var sdks = listSdkProcess.StandardOutput.ReadToEnd();
-                return new DotNetSDKVersions()
-                {
-                    HasDotNet31 = DotNet31Regex.IsMatch(sdks),
-                    HasDotNet50 = DotNet50Regex.IsMatch(sdks),
-                };
+                return DotNet31Regex.IsMatch(sdks);
             }
             return null;
         }

From b02a8cacc28ba629513d5511ab1a5da014758bed Mon Sep 17 00:00:00 2001
From: Victor XField <vxfield@outlook.com>
Date: Tue, 24 Nov 2020 23:18:03 -0800
Subject: [PATCH 09/17] Add global.json and set working directory

(cherry picked from commit 833af12029eedb94c9b2d66a2afe9daea3440a55)
---
 src/QsCompiler/LanguageServer/LanguageServer.cs     | 2 +-
 src/QsCompiler/LanguageServer/LanguageServer.csproj | 8 ++++++++
 src/QsCompiler/LanguageServer/Program.cs            | 5 +++++
 src/QsCompiler/LanguageServer/global.json           | 6 ++++++
 4 files changed, 20 insertions(+), 1 deletion(-)
 create mode 100644 src/QsCompiler/LanguageServer/global.json

diff --git a/src/QsCompiler/LanguageServer/LanguageServer.cs b/src/QsCompiler/LanguageServer/LanguageServer.cs
index 8d708aa89b..6a29b7baf2 100644
--- a/src/QsCompiler/LanguageServer/LanguageServer.cs
+++ b/src/QsCompiler/LanguageServer/LanguageServer.cs
@@ -146,7 +146,7 @@ internal async void CheckDotNetSdkVersion()
                     var downloadAction = new MessageActionItem { Title = "Download" };
                     var cancelAction = new MessageActionItem { Title = "No, thanks" };
                     var selectedAction = await this.ShowDialogInWindowAsync(
-                        "Quantum Development Kit Extension requires .NET Core SDK 3.1 to work properly. Please install .NET Core SDK 3.1.",
+                        "Quantum Development Kit Extension requires .NET Core SDK 3.1 to work properly. Please install .NET Core SDK 3.1 and restart Visual Studio.",
                         MessageType.Error,
                         new[] { downloadAction, cancelAction });
                     if (selectedAction != null
diff --git a/src/QsCompiler/LanguageServer/LanguageServer.csproj b/src/QsCompiler/LanguageServer/LanguageServer.csproj
index 92975a783c..58e2c233a4 100644
--- a/src/QsCompiler/LanguageServer/LanguageServer.csproj
+++ b/src/QsCompiler/LanguageServer/LanguageServer.csproj
@@ -12,6 +12,9 @@
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|AnyCPU'">
     <DefineConstants>DEBUG;TRACE</DefineConstants>
   </PropertyGroup>
+  <ItemGroup>
+    <None Remove="global.json" />
+  </ItemGroup>
   <ItemGroup>
     <ProjectReference Include="..\CompilationManager\CompilationManager.csproj">
       <Private>true</Private>
@@ -37,4 +40,9 @@
   <ItemGroup>
     <AdditionalFiles Include="..\..\Common\stylecop.json" Link="stylecop.json" />
   </ItemGroup>
+  <ItemGroup>
+    <Content Include="global.json">
+      <CopyToOutputDirectory>Always</CopyToOutputDirectory>
+    </Content>
+  </ItemGroup>
 </Project>
diff --git a/src/QsCompiler/LanguageServer/Program.cs b/src/QsCompiler/LanguageServer/Program.cs
index 16f4e4cbbf..c566d16d64 100644
--- a/src/QsCompiler/LanguageServer/Program.cs
+++ b/src/QsCompiler/LanguageServer/Program.cs
@@ -83,6 +83,11 @@ private static int LogAndExit(ReturnCode code, string? logFile = null, string? m
 
         public static int Main(string[] args)
         {
+            // We need to set the current directory to the same directory of
+            // the LanguageServer executable so that it will pick the global.json file
+            // and force the MSBuildLocator to use .NET Core SDK 3.1
+            Directory.SetCurrentDirectory(AppDomain.CurrentDomain.BaseDirectory);
+
             var parser = new Parser(parser => parser.HelpWriter = null); // we want our own custom format for the version info
             var options = parser.ParseArguments<Options>(args);
             return options.MapResult(
diff --git a/src/QsCompiler/LanguageServer/global.json b/src/QsCompiler/LanguageServer/global.json
new file mode 100644
index 0000000000..0b2cf8aa3c
--- /dev/null
+++ b/src/QsCompiler/LanguageServer/global.json
@@ -0,0 +1,6 @@
+{
+  "sdk": {
+    "version": "3.1.100",
+    "rollForward": "latestFeature"
+  }
+}

From 4f89b230b3fa092500ead3227ac51edcedc404fc Mon Sep 17 00:00:00 2001
From: Victor XField <vxfield@outlook.com>
Date: Wed, 25 Nov 2020 00:23:13 -0800
Subject: [PATCH 10/17] Continue to start the server even if there were issues
 with the MSBuildLocator

(cherry picked from commit 64d7d110cf49f2d4c6855634b5a60ae66ba39535)
---
 src/QsCompiler/LanguageServer/LanguageServer.cs | 3 ++-
 src/QsCompiler/LanguageServer/Program.cs        | 1 -
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/QsCompiler/LanguageServer/LanguageServer.cs b/src/QsCompiler/LanguageServer/LanguageServer.cs
index 6a29b7baf2..515c811565 100644
--- a/src/QsCompiler/LanguageServer/LanguageServer.cs
+++ b/src/QsCompiler/LanguageServer/LanguageServer.cs
@@ -155,7 +155,8 @@ internal async void CheckDotNetSdkVersion()
                         Process.Start(new ProcessStartInfo
                         {
                             FileName = dotnet31Url,
-                            UseShellExecute = true
+                            UseShellExecute = true,
+                            CreateNoWindow = true,
                         });
                     }
                 }
diff --git a/src/QsCompiler/LanguageServer/Program.cs b/src/QsCompiler/LanguageServer/Program.cs
index c566d16d64..eb5849195d 100644
--- a/src/QsCompiler/LanguageServer/Program.cs
+++ b/src/QsCompiler/LanguageServer/Program.cs
@@ -126,7 +126,6 @@ private static int Run(Options options)
             catch (Exception ex)
             {
                 Log("[ERROR] MsBuildLocator could not register defaults.", options.LogFile);
-                return LogAndExit(ReturnCode.MSBUILD_UNINITIALIZED, options.LogFile, ex.ToString());
             }
 
             QsLanguageServer server;

From d8462ceac7f642d095e20aa5262edaceb7ceb244 Mon Sep 17 00:00:00 2001
From: Victor XField <vxfield@outlook.com>
Date: Wed, 25 Nov 2020 01:13:35 -0800
Subject: [PATCH 11/17] Add comments to MsBuildLocator exception handling

(cherry picked from commit dc99a4b8f9a8a7d32434555ad10583affb604ee9)
---
 src/QsCompiler/LanguageServer/Program.cs | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/QsCompiler/LanguageServer/Program.cs b/src/QsCompiler/LanguageServer/Program.cs
index eb5849195d..a5a7445ca5 100644
--- a/src/QsCompiler/LanguageServer/Program.cs
+++ b/src/QsCompiler/LanguageServer/Program.cs
@@ -126,6 +126,9 @@ private static int Run(Options options)
             catch (Exception ex)
             {
                 Log("[ERROR] MsBuildLocator could not register defaults.", options.LogFile);
+                // Don't exit here, since exiting without establishing a connection will result in a cryptic failure of the extension. 
+                // Instead, we proceed to create a server instance and establish the connection. 
+                // Any errors can then be properly processed via the standard server-client communication as needed. 
             }
 
             QsLanguageServer server;

From e11e1586b865ce7315b145cd8f1614e7d56f9d7f Mon Sep 17 00:00:00 2001
From: Victor XField <vxfield@outlook.com>
Date: Thu, 14 Jan 2021 14:07:50 -0800
Subject: [PATCH 12/17] Use .NET 5.0 SDK and build the Language Server to
 target the 5.0 runtime

---
 build/init.yml                                      | 4 ++--
 src/QsCompiler/LanguageServer/LanguageServer.csproj | 3 ++-
 2 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/build/init.yml b/build/init.yml
index a8475046fe..6cfa433ea5 100644
--- a/build/init.yml
+++ b/build/init.yml
@@ -16,7 +16,7 @@ steps:
     versionSpec: '5.6.0'
 
 - task: UseDotNet@2
-  displayName: 'Use .NET Core SDK 3.1.300'
+  displayName: 'Use .NET SDK 5.0.101'
   inputs:
     packageType: sdk
-    version: '3.1.300'
\ No newline at end of file
+    version: '5.0.101'
diff --git a/src/QsCompiler/LanguageServer/LanguageServer.csproj b/src/QsCompiler/LanguageServer/LanguageServer.csproj
index 58e2c233a4..067a78ddaa 100644
--- a/src/QsCompiler/LanguageServer/LanguageServer.csproj
+++ b/src/QsCompiler/LanguageServer/LanguageServer.csproj
@@ -2,12 +2,13 @@
   <Import Project="..\..\Common\AssemblyCommon.props" />
   <PropertyGroup>
     <AssemblyName>Microsoft.Quantum.QsLanguageServer</AssemblyName>
-    <TargetFramework>netcoreapp3.1</TargetFramework>
+    <TargetFramework>net5.0</TargetFramework>
     <OutputType>Exe</OutputType>
   </PropertyGroup>
   <PropertyGroup>
     <!-- Workaround for https://github.com/dotnet/cli/issues/9514, see https://stackoverflow.com/a/51644988/267841. -->
     <TargetLatestRuntimePatch>true</TargetLatestRuntimePatch>
+    <AutoGenerateBindingRedirects>true</AutoGenerateBindingRedirects>
   </PropertyGroup>
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|AnyCPU'">
     <DefineConstants>DEBUG;TRACE</DefineConstants>

From a98f62400a1a7f720c31977f7bce29f724b329b7 Mon Sep 17 00:00:00 2001
From: Sarah Marshall <sarah.marshall@microsoft.com>
Date: Tue, 19 Jan 2021 13:29:56 -0800
Subject: [PATCH 13/17] Revert "Use .NET 5.0 SDK and build the Language Server
 to target the 5.0 runtime"

This reverts commit e11e1586b865ce7315b145cd8f1614e7d56f9d7f.
---
 build/init.yml                                      | 4 ++--
 src/QsCompiler/LanguageServer/LanguageServer.csproj | 3 +--
 2 files changed, 3 insertions(+), 4 deletions(-)

diff --git a/build/init.yml b/build/init.yml
index 6cfa433ea5..a8475046fe 100644
--- a/build/init.yml
+++ b/build/init.yml
@@ -16,7 +16,7 @@ steps:
     versionSpec: '5.6.0'
 
 - task: UseDotNet@2
-  displayName: 'Use .NET SDK 5.0.101'
+  displayName: 'Use .NET Core SDK 3.1.300'
   inputs:
     packageType: sdk
-    version: '5.0.101'
+    version: '3.1.300'
\ No newline at end of file
diff --git a/src/QsCompiler/LanguageServer/LanguageServer.csproj b/src/QsCompiler/LanguageServer/LanguageServer.csproj
index 067a78ddaa..58e2c233a4 100644
--- a/src/QsCompiler/LanguageServer/LanguageServer.csproj
+++ b/src/QsCompiler/LanguageServer/LanguageServer.csproj
@@ -2,13 +2,12 @@
   <Import Project="..\..\Common\AssemblyCommon.props" />
   <PropertyGroup>
     <AssemblyName>Microsoft.Quantum.QsLanguageServer</AssemblyName>
-    <TargetFramework>net5.0</TargetFramework>
+    <TargetFramework>netcoreapp3.1</TargetFramework>
     <OutputType>Exe</OutputType>
   </PropertyGroup>
   <PropertyGroup>
     <!-- Workaround for https://github.com/dotnet/cli/issues/9514, see https://stackoverflow.com/a/51644988/267841. -->
     <TargetLatestRuntimePatch>true</TargetLatestRuntimePatch>
-    <AutoGenerateBindingRedirects>true</AutoGenerateBindingRedirects>
   </PropertyGroup>
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|AnyCPU'">
     <DefineConstants>DEBUG;TRACE</DefineConstants>

From 9388319e8b2016eeb4f1852a4ab2decde2562c0c Mon Sep 17 00:00:00 2001
From: Sarah Marshall <sarah.marshall@microsoft.com>
Date: Tue, 19 Jan 2021 13:41:55 -0800
Subject: [PATCH 14/17] Fix warnings

---
 src/QsCompiler/LanguageServer/Program.cs | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/src/QsCompiler/LanguageServer/Program.cs b/src/QsCompiler/LanguageServer/Program.cs
index afd6fff85d..3c79e8e2f8 100644
--- a/src/QsCompiler/LanguageServer/Program.cs
+++ b/src/QsCompiler/LanguageServer/Program.cs
@@ -123,12 +123,13 @@ private static int Run(Options options)
                     return null;
                 };
             }
-            catch (Exception ex)
+            catch (Exception)
             {
                 Log("[ERROR] MsBuildLocator could not register defaults.", options.LogFile);
-                // Don't exit here, since exiting without establishing a connection will result in a cryptic failure of the extension. 
-                // Instead, we proceed to create a server instance and establish the connection. 
-                // Any errors can then be properly processed via the standard server-client communication as needed. 
+
+                // Don't exit here, since exiting without establishing a connection will result in a cryptic failure of the extension.
+                // Instead, we proceed to create a server instance and establish the connection.
+                // Any errors can then be properly processed via the standard server-client communication as needed.
             }
 
             QsLanguageServer server;

From 3ce2822ccdde772fe857cc242c8b7e297b3f84ce Mon Sep 17 00:00:00 2001
From: Sarah Marshall <sarah.marshall@microsoft.com>
Date: Tue, 19 Jan 2021 13:59:22 -0800
Subject: [PATCH 15/17] Rename global.json

---
 src/QsCompiler/LanguageServer/LanguageServer.csproj      | 9 +++------
 .../{global.json => global.language-server.json}         | 0
 2 files changed, 3 insertions(+), 6 deletions(-)
 rename src/QsCompiler/LanguageServer/{global.json => global.language-server.json} (100%)

diff --git a/src/QsCompiler/LanguageServer/LanguageServer.csproj b/src/QsCompiler/LanguageServer/LanguageServer.csproj
index ea07f5f9c5..5e0c4656cf 100644
--- a/src/QsCompiler/LanguageServer/LanguageServer.csproj
+++ b/src/QsCompiler/LanguageServer/LanguageServer.csproj
@@ -12,9 +12,6 @@
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|AnyCPU'">
     <DefineConstants>DEBUG;TRACE</DefineConstants>
   </PropertyGroup>
-  <ItemGroup>
-    <None Remove="global.json" />
-  </ItemGroup>
   <ItemGroup>
     <ProjectReference Include="..\CompilationManager\CompilationManager.csproj">
       <Private>true</Private>
@@ -37,8 +34,8 @@
     <Compile Include="..\..\Common\DelaySign.cs" Link="Properties\DelaySign.cs" />
   </ItemGroup>
   <ItemGroup>
-    <Content Include="global.json">
-      <CopyToOutputDirectory>Always</CopyToOutputDirectory>
-    </Content>
+    <None Include="global.language-server.json" Link="global.json">
+      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
+    </None>
   </ItemGroup>
 </Project>
diff --git a/src/QsCompiler/LanguageServer/global.json b/src/QsCompiler/LanguageServer/global.language-server.json
similarity index 100%
rename from src/QsCompiler/LanguageServer/global.json
rename to src/QsCompiler/LanguageServer/global.language-server.json

From 38676d25dd3835694e272cd4695f096de0821769 Mon Sep 17 00:00:00 2001
From: Sarah Marshall <sarah.marshall@microsoft.com>
Date: Tue, 19 Jan 2021 14:03:13 -0800
Subject: [PATCH 16/17] Preserve log of exception

---
 src/QsCompiler/LanguageServer/Program.cs | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/src/QsCompiler/LanguageServer/Program.cs b/src/QsCompiler/LanguageServer/Program.cs
index 3c79e8e2f8..5115feddd6 100644
--- a/src/QsCompiler/LanguageServer/Program.cs
+++ b/src/QsCompiler/LanguageServer/Program.cs
@@ -123,13 +123,13 @@ private static int Run(Options options)
                     return null;
                 };
             }
-            catch (Exception)
+            catch (Exception ex)
             {
-                Log("[ERROR] MsBuildLocator could not register defaults.", options.LogFile);
-
                 // Don't exit here, since exiting without establishing a connection will result in a cryptic failure of the extension.
                 // Instead, we proceed to create a server instance and establish the connection.
                 // Any errors can then be properly processed via the standard server-client communication as needed.
+                Log("[ERROR] MsBuildLocator could not register defaults.", options.LogFile);
+                Log(ex, options.LogFile);
             }
 
             QsLanguageServer server;

From 2d9c1b458ffffdb06eab3450eff31c358163db77 Mon Sep 17 00:00:00 2001
From: Sarah Marshall <sarah.marshall@microsoft.com>
Date: Tue, 19 Jan 2021 15:59:23 -0800
Subject: [PATCH 17/17] Check null from Process.Start

---
 src/QsCompiler/LanguageServer/Utils.cs | 26 +++++++++++---------------
 1 file changed, 11 insertions(+), 15 deletions(-)

diff --git a/src/QsCompiler/LanguageServer/Utils.cs b/src/QsCompiler/LanguageServer/Utils.cs
index 414e30c99e..105c4f447a 100644
--- a/src/QsCompiler/LanguageServer/Utils.cs
+++ b/src/QsCompiler/LanguageServer/Utils.cs
@@ -149,23 +149,19 @@ internal static class DotNetSdkHelper
 
         public static bool? IsDotNet31Installed()
         {
-            var listSdkProcess = Process.Start(
-                new ProcessStartInfo()
-                {
-                    FileName = "dotnet",
-                    Arguments = "--list-sdks",
-                    RedirectStandardOutput = true,
-                });
-            if (listSdkProcess.WaitForExit(3000))
+            var process = Process.Start(new ProcessStartInfo
             {
-                if (listSdkProcess.ExitCode != 0)
-                {
-                    return null;
-                }
-                var sdks = listSdkProcess.StandardOutput.ReadToEnd();
-                return DotNet31Regex.IsMatch(sdks);
+                FileName = "dotnet",
+                Arguments = "--list-sdks",
+                RedirectStandardOutput = true,
+            });
+            if (process?.WaitForExit(3000) != true || process.ExitCode != 0)
+            {
+                return null;
             }
-            return null;
+
+            var sdks = process.StandardOutput.ReadToEnd();
+            return DotNet31Regex.IsMatch(sdks);
         }
     }
 }