PowerShell无法在Windows 2008 R2上运行

Question

I have accidently installed .Net 4.5 on my Windows Server 2008 R2 for PowerShell 5.1, but now I have reverted to .Net 4.0 version and now the PowerShell is not working. It gives below error.

Windows PowerShell terminated with the following error: Method not found: 'System.Threading.Tasks.Task System.Threading.Tasks.Task.Run(System.Action)'

What should I do to resolve this?

Answer 1

Perhaps this is the same issue you have: https://michlstechblog.info/blog/powershell-method-not-found-system-threading-tasks-task-system-threading-tasks-task-runsystem-action/

If that does not work for you, you can always reinstall Powershell 3.0. Download it from https://www.microsoft.com/en-us/download/details.aspx?id=34595

You can also install a higher version if you would like. It would do no harm. Reinstall will require a reboot as they come in the form of KBs.

Answer 2

You will need to download Windows Management Framework 3.0 or install Microsoft .NET Framework 4.5 to correct your issue.

Windows Management Framework 3.0 - link

Microsoft .NET Framework 4.0 - link

or you can get

Windows Management Framework 4.0 - link

Microsoft .NET Framework 4.5 - link