We have ZENworks 11.4.2 running on Windows Server 2012 R2 and connected to an AD user source. Everything was running fine until we noticed all the RAM being used. We powered down the ZENworks server and doubled the RAM, making it now 8GB. There were also some GPOs that were edited. The next morning, we found that all AD users were being locked out of Windows as soon as they logged in. We found it to be a GPO changed and disabled the GPO until a later date. During that time, because the users were being locked out, we could not log into Zenworks. After we got the Windows accounts fixed and unlocked, I noticed that only Domain Admins can log into Zenworks. When a domain user logs in, they get the error "Unable to log into the network because the login credentials are incorrect." I have never seen this error before. It is very confusing since all the Domain Admins can log in with no issues. If I make a domain user into a domain admin, they can login just fine. The user source is connected just fine. I have made almost every change in the registry I could find. I have re-installed Zenworks and I still get the same error. I need this working immediately as Zenworks pushes out important data.