We aren't loading a game, we are attempting to start a new one. Neither of us have any error-log texts either.
Odd, definitely not heard of people hitting that lately. What map seed and settings? If I can reproduce the problem on my end I can probably fix it, but if I can't, I probably can't.
A few things you've probably tried, but making sure:
- Try with different map seeds.
- Try with different settings (notably, with everything off, and with everything on).
- Try starting a new game in single player and then loading it in multiplayer (this doesn't give you quite the scenario you want, of course, just testing that it works or doesn't work).
- If either of you have alternate computers, try with those. Particularly if they're in different networks.