Runtime Error Fix?

I play Civ V on Steam, and recently I've been experiencing a runtime error whenever I try to load a game. The gameplay is fine, and my computer is updated and running at the correct specs. Any advice?

Besides to normal - upload the dxdiag (in the support section) and wait for one of the brainaics over here (or at the 2k forum) to answer.

In general:
http://windows.microsoft.com/en-gb/windows-vista/what-is-a-runtime-error