When you open your project, besides the audio conforming, the other thing that Premiere is doing is generating thumbnails for all the clips in the project window & for your timeline, assuming you're displaying thumbnails.
My bet is that one particular clip is crashing on decode, possibly due to a corrupted frame 0 at the start of a clip. This would also make sense since there were some MPEG fixes made to the indexing previously, Premiere would always reject the first two frames of an MPEG stream without checking whether the first GOP was closed. Now, it respects a closed GOP properly, but if an MPEG file is malformed, this could be the problem.
I would try to see if you can isolate the problem to a particular clip, either by making a copy of the project, removing half the clips in the project, see if it crashes, & repeat until you narrow down the specific clip, or alternatively by trying to import the same clips one at a time in a new project.