Oh my sweet Lord, tried to upgrade, it all looked fine, no errors and then vegas will not load at all… I removed it, reloaded the original version I had, that one will not work either…, removed that one, used the new one, wont work either….. Im glad I always make backups before doing any changes to any software I cant live without and 4 hours later I am back with a working system… I have a few other pc’s so I am going to try a few more scenarios and see if I have the same problem in those…. That is why I never ever upgrade unless I have a good reason (this one sounded like a good reason).
Now, this is interesting, I can see sony avc on its own and it has the same extension as what you have in your screen shot but not the MVC part in the name… Could it be that the option only shows when using a particular file format?