If you have or set threads and modules on all is good .
If you then disable to go back to default PL closes but doesn't show up in system tray and you have to close PL GUI in task manager and restart it .
What seems to happen is governor crashes I think, its not shown in task-manager . Its not 100% repeatable but if you do toggle the setting it will crash (not show PL ) after one or two times .
Also just restarting PL won't help until you close out the instance in task-manager first .
PL version 6.6.0.12 , Win7 64
Thanks for the report! I'll check into it.