I tried restarting my computer, which, of course, didn't work. I tried unleashing the full force of all my virus and malware scanners, to no avail. Finally, I broke down and called Adobe support. I'll give it to the guy who tried to help me, he must've gone through every solution in his manual. Even so, I was on the phone for over two hours, only to have it end with "It's not a problem with our product, it's a problem with your .NET Framework." How did we figure that out? By doing something we could have done in the first five minutes of the call, instead of the last, but the tech support manual told him not to tell me to do. So you don't have to wait on the phone for hours and miss days of productivity, here's a quick and easy way to determine if your problem is the .NET Framework and how to fix it in about 10 minutes.