Sweet! Thanks. That worked for me, I think. It's probably the latest DLL version after all. Using v45 now and it's working fine.
EDIT2: Or so I thought >.< As it turned out, after playing it some length into it, it crashed again. I don't think it has anything in particular to do with specific AI turns. Previously, I thought it was because of certain wonders I built. Some trial and error proved that wrong. I suspected it was certain turn numbers, but it doesn't seem to be the case either (it varies).
I doubt it's got to do with specific civilizations. Each time I play, I randomize the opponent civilizations, so they're not the same ones each time. Their actions are pretty random in all cases as well, probably corresponding to their respective personalities so I guess that might not be the reason either.
I'll either edit this post or make a separate post with a link to the save later after I try again (and make a save closer to the turn it crashes).
EDIT3: Here you go. I don't see any common links between the crashes. Seems really random if you ask me. Hopefully you'll have better luck finding out what went wrong. Is it a problem on my end, or is it a bug for real? Anyway, here's the link to the save. I saved every turn so this one happens to be one turn before it crashed for me.
https://www.dropbox.com/s/cch88qpguj03hk1/QuickSave.Civ5Save
That said, I have a feeling since its so random, there's probably a chance it doesn't crash in the next turn for you. I would suggest you just let a few turns go by first just to see if it holds up.