computer crash

In elements 2018 I was using the content aware tool and trying to extend a photo, I am a beginner but things seemed to go OK.

With the same photo I then changed to the clone tool and noticed there was no circle but a load of squiggly lines instead.

The clone tool worked, but I still had lines and not a circle.

I then had a message saying cannot complete, and my computer shut down and then re started.

I opened Elements 2018 and the clone tool was still all lines and blotches of about a third of the screen.

Another message saying cannot complete and my computer shut down.

This time however it opened up on a repair screen, but I failed to repair it, so ended up re loading windows 10 and all my software

which took the best part of a day.

Why did I have this meltdown from Elements (nothing else was running), I am now scared to try the program again in case the same thing happens.

Any comments or help would be appreciated.