So far I've only had a problem starting one program. When I tried to run eM Client I got the spinning circle then nothing. I tried three times with same results. Then I tried rebooting the computer and running eM Client again. First I got the spinning circle. The second time I got a message about looking for a corrupt data base. Went into services and disabled eM Client and tried running it again. I got the same message about a corrupt data base. Then it loaded and has been running fine. I'm not home now I'll test it more when I get home. Testing the new build on my Lumia 640XL. So far so good.