I've bought Dawnguard in Steam and have downloaded all necessary files, but game crashes before text in main menu appears. Checking cash, reinstalling etc doesn't help(. Game works only without enabled DLC. Please repair it or take my money back.
EDIT: Dawnguard works only with ENGLISH lang (not with RUSSIAN)

Same thing here, use Russian licensed version of Skyrim. Hope they 've done something about it in 1.7 patch coming.

well, I had the same problem and found a solution )
- go to steam
- select skyrim (naturally--> what else? )
-open the properties (click with right key)
-choose the register local files
- click third option (check gamefiles for errors or something like that (sorry mine is in german ))
if you're lucky there are 2 files which could not be checked and they will be downloaded anew --> tadaaaah you can play
hope everything works )

U mean the Steam cache? That was the first thing I tried. It's useless. There is no working solution mentioned in this forum, something definately new is needed.

well, that svcks o.O
worked for me, so sorry, but... i'm happy