This is a first for me.  When Vegas Pro 11 64-bit Crashed a little while ago, (that makes about 20 times today alone)  I tried to open the project and I get this lovely message.
 "an error occurred whilst loading the project file. The file is most likely corrupted or of an unknown format"
Now I'm set back a few hours.  I just updated and get the same error.
Oh, and the same error for the auto file vegas made.
Any suggestions?