I am going to be a bit unkind about this, because I think you know better. You're copping out because you won't consider the user's point of view.

I know you have put time and effort into this, but if you are still experienceing user-related problems, the system is not user-friendly. There is a rhythm to the way people do their jobs, and your system has to present questions and accept data in a way that people can follow. If you want good data, you have to make the entry lines flow in a way that's logical to the user. You have to make the screens flow from one to the next, also in a way that's logical to the user. You have to make it difficult for them to go wrong.

You and your tech people have probably got a list of common user problems and have probably created a knowledge base of solutions for the new tech people. You can use that information when you update your system. Make the problem fixes, in lay terms, pop up on the screen when an entry must be rejected on the system, and have the system take the cursor back to the point where the correction is needed.

I use a couple different vendors to design postcards online for advertising. Their systems look similar but one hangs up constantly; the technical support people for that vendor keep telling me to clear the cookies and other caches on my computer, and to try a different web browser. That's the online equivalent of RTFM, and the tech people there probably complain about lazy, stupid users. The other vendor's systems works a lot better and I never need to talk to their tech support people.