"Multiple Instances of this application's Installer are running. This one will stop and let another complete."
I just got this when I tried to enter Spiral Knights. I've played many times before, and this only just started happening. It won't let me play! I have tried restarting Steam entirely, checking through processes to see if another instance of Spiral Knights existed (it didn't) I even reinstalled the game (twice!). Anyone got an idea of why this is happening?
Cheers!