What is AWS?

Amazon Web Services.

I have clients on AWS and they never get this error.  I doubt AWS is the problem, they just give you a remote Windows server.  This is a sign of an improper installation, because users are losing their security settings.  Once any control is registered, it should not have to be registered.  You are talking about an AWS server where users are logging into RDP sessions, right?

I agree. IT person is checking on connectivity problems too.

Connectivity problems should not cause this error. Are Sage and the SQL database installed on the same single AWS server?

Cannot create control usually caused by the followings:

1. UI is not registered - run Regacc.exe in runtime to see if it helps.

2. Database is not upgrade/activate properly - try to load Sample company and activate database to see if it is the cause.

3. User rights - run Sage 300 as administrator to see if it resolved the issue.

Thanks. I will try this. The point is that this happens randomly.

If it happens randomly, then REGACC and Run as Administrator are not the issue.  Those only have to done once on a new install.  If you don't install a new version or service pack, then neither should be necessary again.