This is a default for all hard crashes that PTC cannot explain. I get all the time when working with a new function and the system just trips up. I've reported it before but there is little they can do without a repeatable error.
Having said that, I've also had a corrupted file continuously crash with a fatal error. it was a part file with a few images placed on datum planes for an underlay. The file got confused as to what image was what and until I removed all these (back-tracked), that part and anything that used it was unusable.
Since you are having problems only in assemblies, either your start assembly part is corrupt or a file you are consistently inserting into your assembly is corrupt but works on its own, but not in the assembly.
PTC does take hard crashes very seriously. If you can reproduce it and provide a support case along with the files, they will look into it. But the crashlog and all the associated files does them little good. I had a support tech tell me as much. Sometimes a Trail file will help, but even then, they are often random occurrences.
The thing you were referring to is changing the OpenGL graphics support to GDI_32 (or whatever) in config.pro. It is -not- a solution as your overall graphics performance would suffer. This is the case when the graphics driver and hardware are not supported by PTC and Creo and the OpenGL simply fouls the plumbing and causes crashes. But this would be from day one... not something that just start getting worse.
