My knowledge is pretty basic but since you haven’t gotten a response, I will throw something out there because I recently had an issue similar to yours. Maybe it will help find a fix. I had upgraded from Windows 7 to 10 and done a complete “clean-out” and re-install of all software. Vegas Pro 14 worked for editing but when I would hit the render button, nothing would happen, just the spinning blue circle. In addition, I couldn’t get Adobe After Effects to open at all. But all other programs opened and functioned fine. Here is the short version: we unhooked the C: drive and then hooked it back up and all works now. The longer version is that I tried all the steps you tried, finally called in a computer expert, he couldn’t find the problem. After working on it for a couple of hours, he decided to clone my C drive to a SSD he had and take it home to work with it on his computer. Once he cloned the C drive, he decided to plug the SSD into my computer just to see what it would do. Vegas render worked and After Effects worked. He then decided to plug my C drive back in and everything worked and has been working ever since. Go figure. Neither of us know why, maybe connectors not quite connected fully, we don’t know. But, since my issues seems similar to yours, I thought I would put it out there and see if it can help. Hope it does even though I can’t answer as to why it worked.