Bump: Just found this on the 2K forums. Anyone getting these runtime crashes, try this fix:
It works!
Steps taken:
1. Disable steam cloud synchronization (steam -> settings -> downloads+cloud)
2. Take steam offline (steam -> go offline)
Result:
Game no longer crashes when I click "Load Game". I can load games successfully.
Seems 5 people have tried this and it's fixed their issue. It doesn't seem to work for -everyone-, 2 users reported issues still, but it's worth a shot. If you're getting this issue, try running the game unsynched and offline. I intend to try it myself when I get home so that I can finish painting the free world Red as the mighty USSR (Thank you Civ 5 mod community for the USSR + Stalin mods
)