Thanks to the save games provided, I've tracked down one issue that may have been causing the CtD's. It wasn't something I would really have expected or looked for without the saves, so thanks for that.
The problem would have affected Professors, Wyvern Guard, Coatlann and Misquiztli. This would also explain the "occasional" CtD's reported pre-020 (Professors) and the increased rate post-020 (Wyvern Guard).
I've made the fix to those units and tried an AI-only game at Quick Speed using all 5 new races - no CtD's for the first 400 turns (at which point I decided to stop the test as the time between turns was becoming significant).
I can't promise that this will resolve the issue for everyone, though if it was working the way I think it was, it would have been a fairly significant cause of CtD's, on a fairly intermittent basis.
The fix should not break save games and will (hopefully) apply retroactively to games already in progress. For those games that are saved right at the point of a CtD, you may need to roll back by 1 additional auto-save point to correct any units already created that would have caused the problem. It may still work for those units, but I'm not convinced it should.
I've also bundled a few other minor fixes that I can get away with and still keep save-games intact into this patch, based on the feedback so far. See the
Patch Post for the full list of changes.
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Thanks again for the feedback. As for the bugs - you keep finding them, I'll keep trying to fix them
