When my internet service was completely out for several days, I could not launch MC 8.5.x at all. The launch wouldn't even get as far as the splash screen before crashing to the desktop. I went through multiple uninstalls and reinstalls with nothing changing. The same thing occurred with or without App Man installed or with or without it running.
When I reverted to 8.2 (which was working on another machine), it would launch and run.
Now that my internet service has been back up consistently for several days, I've just reinstalled MC 8.5.2 on this machine and it runs just as it did before the internet service problem.
This is exactly why I stuck with the dongle when software activation came along a few years ago. I didn't want any difficulties if either internet service or activation servers weren't working.
Someone please try to explain why with a dongle I had any of this trouble at all. I can't imagine any reasonable explanation.