Add-Type 'DateTime' not recognized

[Rtw915]

I think it is a bug

I have a script that run fine in ISE or the console but would not run in PRTG.

in PRTG it would output this in the log file:

(1) :     using System;
At C:\Program Files\WindowsPowerShell\Modules\PoshRSJob\1.7.4.4\PoshRSJob.psm1:51 char:5
+     Add-Type @"
+     ~~~~~~~~~~~
    + CategoryInfo          : InvalidData: (Microsoft.Power...peCompilerError:AddTypeCompilerErro 
   r) [Add-Type], Exception
    + FullyQualifiedErrorId : SOURCE_CODE_ERROR,Microsoft.PowerShell.Commands.AddTypeCommand
 
WARNING: (0) : No source files specified

(1) :     using System;
Add-Type : Cannot add type. Compilation errors occurred.
At C:\Program Files\WindowsPowerShell\Modules\PoshRSJob\1.7.4.4\PoshRSJob.psm1:51 char:5
+     Add-Type @"
+     ~~~~~~~~~~~
    + CategoryInfo          : InvalidData: (:) [Add-Type], InvalidOperationException
    + FullyQualifiedErrorId : COMPILER_ERRORS,Microsoft.PowerShell.Commands.AddTypeCommand
 
Unable to find type [RSJob].
At C:\Program Files\WindowsPowerShell\Modules\PoshRSJob\1.7.4.4\Public\Get-RSJob.ps1:72 char:9
+         [RSJob[]]$Job,
+         ~~~~~~~~~
    + CategoryInfo          : InvalidOperation: (RSJob:TypeName) [], RuntimeException
    + FullyQualifiedErrorId : TypeNotFound
 
Unable to find type [RSJob].
At C:\Program Files\WindowsPowerShell\Modules\PoshRSJob\1.7.4.4\Public\Get-RSJob.ps1:72 char:9
+         [RSJob[]]$Job,
+         ~~~~~~~~~
    + CategoryInfo          : InvalidOperation: (RSJob:TypeName) [], RuntimeException
    + FullyQualifiedErrorId : TypeNotFound

After searching for the issue I found this:
https://social.technet.microsoft.com/Forums/windows/en-US/c8467128-ab64-4920-8697-3cc76e901568/addtype-usage?forum=winserverpowershell

In PoshRSJob.psm1 I changed line 72 from:

public DateTime LastActivity = DateTime.MinValue;
to
public System.DateTime LastActivity = System.DateTime.MinValue;

It now appears to work.