Device Control can't activate mass storage devices

Question

Hello Sophos Community, 
 I have a problem with Device Control. It seems it cant activate exceptions for Device Control for our normal users. If I try it with an admin account it works fine. I had a look at our GPOs and I guess the problem is, that programms cant change registry settings, when non admins are logged in. Am I correct there? If thats the case: is there a workaround? 
 Greetings

David Do Van · Answer

Hi, 
 After a while of reasearch, I found the problem was a Web Cache with corrupted Data. I cleared the Cache and now it works like a charm. 
 Thx