diff --git a/src/Microsoft.VisualStudio.SolutionPersistence/Errors.Designer.cs b/src/Microsoft.VisualStudio.SolutionPersistence/Errors.Designer.cs
index 27949b96..1f985ed7 100644
--- a/src/Microsoft.VisualStudio.SolutionPersistence/Errors.Designer.cs
+++ b/src/Microsoft.VisualStudio.SolutionPersistence/Errors.Designer.cs
@@ -206,7 +206,7 @@ internal static string InvalidModelItem {
         
         /// <summary>
         ///   Looks up a localized string similar to Names cannot:
-        ///- contain any of the following characters: / ? : \ * &quot; &lt; &gt; | # &amp; %
+        ///- contain any of the following characters: / ? : \ * &quot; &lt; &gt; |
         ///- contain control characters
         ///- be system reserved names, including &apos;CON&apos;, &apos;AUX&apos;, &apos;PRN&apos;, &apos;COM1&apos; or &apos;LPT2&apos;
         ///- be &apos;.&apos; or &apos;..&apos;.
diff --git a/src/Microsoft.VisualStudio.SolutionPersistence/Errors.resx b/src/Microsoft.VisualStudio.SolutionPersistence/Errors.resx
index 6be5d561..a3755c1b 100644
--- a/src/Microsoft.VisualStudio.SolutionPersistence/Errors.resx
+++ b/src/Microsoft.VisualStudio.SolutionPersistence/Errors.resx
@@ -199,7 +199,7 @@
   </data>
   <data name="InvalidName" xml:space="preserve">
     <value>Names cannot:
-- contain any of the following characters: / ? : \ * " &lt; &gt; | # &amp; %
+- contain any of the following characters: / ? : \ * " &lt; &gt; |
 - contain control characters
 - be system reserved names, including 'CON', 'AUX', 'PRN', 'COM1' or 'LPT2'
 - be '.' or '..'</value>
diff --git a/src/Microsoft.VisualStudio.SolutionPersistence/Model/SolutionModel.cs b/src/Microsoft.VisualStudio.SolutionPersistence/Model/SolutionModel.cs
index cf273d43..5d94160d 100644
--- a/src/Microsoft.VisualStudio.SolutionPersistence/Model/SolutionModel.cs
+++ b/src/Microsoft.VisualStudio.SolutionPersistence/Model/SolutionModel.cs
@@ -14,9 +14,9 @@ namespace Microsoft.VisualStudio.SolutionPersistence.Model;
 public sealed class SolutionModel : PropertyContainerModel
 {
 #if NETFRAMEWORK
-    private const string InvalidNameChars = @"?:&\/*""<>|#%";
+    private const string InvalidNameChars = @"?:\/*""<>|";
 #else
-    private static readonly SearchValues<char> InvalidNameChars = SearchValues.Create(@"?:&\/*""<>|#%");
+    private static readonly SearchValues<char> InvalidNameChars = SearchValues.Create(@"?:\/*""<>|");
 #endif
 
     private readonly VisualStudioProperties visualStudioProperties;
diff --git a/test/Microsoft.VisualStudio.SolutionPersistence.Tests/Serialization/Validation.cs b/test/Microsoft.VisualStudio.SolutionPersistence.Tests/Serialization/Validation.cs
index c240433b..9e260333 100644
--- a/test/Microsoft.VisualStudio.SolutionPersistence.Tests/Serialization/Validation.cs
+++ b/test/Microsoft.VisualStudio.SolutionPersistence.Tests/Serialization/Validation.cs
@@ -88,11 +88,8 @@ public void ConfigurationName()
             ">",
             "?",
             "*",
-            "%",
             ":",
             "|",
-            "&",
-            "%",
             "con",
             "com1",
             "lpt9",
@@ -170,7 +167,7 @@ public void SolutionFolders()
         string invalidNameError = Errors.InvalidName;
 
         // Don't allow invalid characters
-        Assert.StartsWith(invalidNameError, Assert.ThrowsAny<ArgumentException>(() => solution.AddFolder("/Foo#/")).Message);
+        Assert.StartsWith(invalidNameError, Assert.ThrowsAny<ArgumentException>(() => solution.AddFolder("/Foo</")).Message);
 
         // Don't allow reserved names
         Assert.StartsWith(invalidNameError, Assert.ThrowsAny<ArgumentException>(() => solution.AddFolder("/LPT4/")).Message);