I ve got the Ger No Gore Version, recently updated it via Steam and added DM afterwards.....now it is not possible to reach the Main Menu....game does not launch at all...any hints out there ?

PS3 or PC?

When on PC, try to restart Steam and see if it downloads additional files. I had the issue, that when i bought it it only downloaded 110MB and so ingame Dead Money didn't start. After restarting steam its now downloading 342MB. If that does not work, right click on Vegas 'properties' -> 'local files' -> 'verify integrity of game cache', it then checks if some of the files are corrupted and if so reaquires them.

This was the fastest and instantly most helpful hint ever recieved..... thanks Mr Starkiller

Same thing is happening to me. I've cleared local content and redownloaded everything, I've verified the local cache hundreds of times, turned off auto updates, restarted steam and turned them back on again, tried to start NV directly from the executable, tried disabling the caravan pack... I get to the launcher, click "play" and the game dies.

Steam consistently downloads an 808byte file after verifying the cache, but according to google this is unrelated. Right now, I have a $50 game and $10 piece of DLC that immediately puts up "FalloutNV has stopped working...." at every launch *sigh*

edit : in my case, Windows 7 Professional(64) + SP1 + Nvidia GTX260 = crashfest with bethesda games. I uninstalled SP1, and now everything's working fine and dandy again.

Adding to the thread rather than editing :

The culprit was a combination of EVGA Precision and Win7 SP1 - apparently there is a hotfix for a potential graphics subsystem exploit that causes the EVGA Precision or MSI Afterburner OSD servers to crash DX9 games - either uninstall Precision or Afterburner or turn off the OSD servers and the games'll work again.