I had that exact problem when I migrated from a HDD to a SSD on my Dell T3500. Explorer worked on all my other Sony software, i.e., Acid, SprectraLayer Pro, but not Vegas…but that instance is probably related to my drive replacement and since you haven’t made any hardware changes then my experience won’t matter. Like you though, I’m just hoping someone finds an answer. Until then I’ve returned to the original HDD. I did install an SSD on my HP mobile workstation with no problems when using Vegas. Interesting!