I try and start the game, and it says that the launcher failed. I got the log of which file failed to validate:
Starting validation of Fallout New Vegas
Validation failure: c:\program files (x86)\steam\steamapps\common\fallout new vegas\InstallScript.vdf
Validation complete: 435 Total Files, 1 Failed Validation

What does this mean? I have uninstalled and re-installed. When I tried to validate the files, it said that it would be reacquired, but it wasn't and didn't give me any options to do so.
What else can I do to fix this? What kind of file is .vdf on FNV?

REALLY? Nothing from the makers of the game? Don't they even monitor their own website?