OK, so I've learned painfully that Pro/E used to regenerate an assembly according to the model tree. So it would regenerate fine if you assembled component A, assembled component B, then made a cut within the assembly that trims material off of both. This is logical, after all. It works very nicely for showing the machined form of a weldment, where you have components to represent the raw pieces and raw weld shapes. It worked very well back in 2002 or so when these models and drawings were created.
Current Pro/E releases will no longer support this. It will open but not regenerate consistently or correctly. I would just be happy to retrieve the files and view the drawings correctly but that's not happening.
I now know that you need to use a subassembly to hold all of the components, put the subassembly into the main assembly, then apply the assembly cuts in the main assembly. It makes no sense that this should be necessary. We are doing it the "right" way with new models of course, but my problem is legacy models.
Our department has a number of assemblies (including family tables, etc) built in this manner. Each instance of course has it's own drawing. Re-doing them would be torture. Does anyone know a way to solve this problem by restructuring or otherwise fixing things? This also would need to keep the drawings associated and regenerating correctly.