After completing a PC Matic scan, and then selecting to "Fix All", I usually get a results screen at the end.
This time, instead of getting a results screen, I received an error screen, and it directed me to these forums for help. I then had to kill PC Matic, as I couldn't get the error screen to go away. Upon trying to go back in to PC Matic, I received the same thing.
Please see the attached file that shows the last "loading" screen I saw, and the other file, which shows the error screen that I received.