Non responsive UI after coop games

[Aggh]

http://imageshack.us/a/img607/2986/nonresponsiveui.jpg

Been getting this almost every time after a coop game, the only button that works is the logout button.

And when I log out, there's not login in screen:

http://imageshack.us/a/img716/9940/nonresponsiveuilogout.jpg

System specs:

• Coolermaster HAF-932
  
• Coolermaster Hyper Evo 212+
  
• MSI Z77-GD65
  
• i5-2500k @ 4.2 ghz
  
• 8 GB Kingston HyperX DDR3 1600 mhz
  
• EVGA GTX 670 2 GB
  
• Plextor M5S 128 GB SSD
  
• Corsair HX650
  
• Windows 7 home premium 64-bit
  

[Nurdle]

I get this issue too. For me it started happening after I finished all missions in the game. Now everytime I play and complete a mission the whole ui Hangs. Have to close the game via task manager and log back in for it to do it all over again on next mission completion. It's making coop games unbearable for me and my friends