This turns out to become a "how to work with appbuilder" threads, which is a rather big topic. I suggest you try to get a course or do some reading in the documentation.
It would be nice if you would try to be familliar with the appbuilder first.
It is not that difficult.
And if you have any queations then ask that question in a seperate thread.
About the x_u record not on file error. That means the file is corrupted. Probabaly because of an editing error caused by openening the file in Appbuilder. If you can open the file then save it under a different name and compare it with the original one.
Another thing, upgrading form 8.3 to 9.1C seems kinda pointless to me. If you upgrade, do that to the latest version of Progress, which is 10.1C (10.2A is just released, but not yet available to me).
Casper.
Furthermore