Freezing PB windows with Windows 2012

Hello, We see our PB screens are freezing since after the PB upgrade 12.6.

Details : PB version 12.6 compiled in Windows 2012 & Windows SP2 . But these exes were deployed in windows 2008 server due to client has only 2008 servers.

The problem may disappear if users switch the change the settings from "Apply for best appearance" to "Apply for best performance" . But this is not correct option for now as there will be 1000s of users accessing the application and not a feasible solution ask all of them to change this setting.

Any ideas worth!!