I have a Windows 2008 R2 DC on which I try to run a PowerShell script that uses the AD module. The loading itself works, the output of Get-Module shows the ActiveDirectory module with its exported cmdlets. But there is a "small" error message saying that the Given key was not present in the dictionary after Import-Module. The error is no real exception, it's just the text displayed in red.
When I try to execute an AD function like Get-ADUser I finally get a real exception with the same message. When I execute Get-Item AD: I get an exception that the drive could not be found.
I have no idea how to fix this. Can anyone help?
Edit: Another server using RSAT behaves exactly like the DC when trying to load the AD module.