I’ve come across this a few times with Lync 2013 and Server 2012 R2 where the Lync Management Shell just sits loading at _
Then I closed PowerShell and re opened the Lync Management Shell as Admin and it load correctly! awesome so I tried a couple more times and still works.
I did however find you have to do this for each users profile though.
Hopefully this will get you back to a loading Lync Management Shell