This exact problem is happening to me in Windows 5.6.1 ... apparently it returned in 5.6.0? Only happens when unity is connected to my Perforce server (which is remote.) I am getting a lot of FSTAT messages in the console (I have the unity plugin set to Verbose) and every time I click on something it hangs while it does an FSTAT. Sometimes when I switch out of the editor and return Unity hangs up for close to a minute and when it's done there's a half dozen FSTAT messages in the console window. Anyone else seeing this? Any way to fix it?