PowerShell 4 Get-AD Function Issues

I have just been upgraded to Win8.1 at work, and have my PowerShell scripts that worked happily on Win7 (with PowerShell v3). Most work, but I can't seem to get any 'Get-ADUser' or 'Get-ADComputer' commands to work

Whenever I put in:

Get-ADUser username -Properties *

All I'm getting back (this is in the ISE) is the line that I've written above - with no errors.

Can someone please tell me what is going on? I've change the ExecutionPolicy to 'Remote Signed'.