[Mobhack]

problems with custom OOBs can crash the game - especially if the creator used non-English ASCII in any of the text fields (unit information - I recall someone put in Spanish accents, so if the user brought up info for those particular units - BOOM!). Unit info is usually seen in the upgrade screens, as well as the encyclopaedia. Missing SHP file info on custom OOBs (if the user has not loaded these) can also crash things, as can weapons data that does not match.

Corrupt/incorrectly formatted third-party SHP files can also crash the game. So can LBM picture files that are incorrect.

Therefore, I'd suspect your custom data - either OOB or LBM or SHP files (if any).

So to test the theory:
Either - Remove the custom OOBS, and especially any custom SHP and LBM files you may have. Then try the game again.

Or, install the stock game (and patches) to a different installation folder, and see if you still have the problems when playing stock.

Either way, you will soon know.