Powershell Error (show-command)

Hello

Sudenly I've started getting error in PowerShell (all the consoles: regular user, admin user, ISE with regular user, ISE with admin). And also commands tab in ISE is empty. Tried running with /noprofile switch, but with no luck.

OS is Windows 8.1.

Error:

PS C:\Windows\system32> Show-Command
get-command : Object reference not set to an instance of an object.
At line:1 char:3
+ @(get-command -CommandType Cmdlet,Function,Script,ExternalScript,Workflow),@(get ...
+   ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : NotSpecified: (:) [Get-Command], NullReferenceException
    + FullyQualifiedErrorId : System.NullReferenceException,Microsoft.PowerShell.Commands.GetCommandCommand

PSVersionTable:

PS C:\Windows\system32> $PSVersionTable

Name                       Value
----                            -----                         
PSVersion                      4.0                                                                                                                                              
WSManStackVersion       3.0                              
SerializationVersion        1.1.0.1                        
CLRVersion                    4.0.30319.34003          
BuildVersion                  6.3.9600.16394            
PSCompatibleVersions           {1.0, 2.0, 3.0, 4.0}
PSRemotingProtocolVersion      2.2