Shotgun Desktop not opening any apps

Hey all have a big problem here. I have one artist who is having a major issue. He just installed shotgun desktop we launch we get no errors it finds local application and our app we have developed but nothing will launch from his desktop app. Not app like maya not custom apps we have written nothing. I get no errors in the console. We have launched probably 30 artists and all have no problem just one artist. I dont even know where to begin trouble shooting this. Any ideas? He is on windows 10 latest version of shotgun desktop, we have tried uninstalling and reinstalling shotgun desktop and as I said no errors that I can find.