If you upgraded Sony Vegas you’re probably now struggling to open projects saved in previous version. The problem is when you try to open older projects in a newer version, Vegas merges all media files inside the project in a monolithic piece, which practically makes editing such project impossible.
Whatever you do – double click on the project or open it via menu, the result is the same. In fact, to open old project you have to right-click on it and select Edit in Vegas. This time the project opens as it should.