How do I fix Firefox?

Here's the situation. My kids' have their own desktop and use Mozilla Firefox. After a while when they try to use Firefox, it turns on but refuses to show on the screen. I tried cascading the windows, maximizing the windows, everything. But the final solution was to delete their profile and start anew.

I'm using Windows 8 because I refuse to use Windows 10 especially after all the pure fecal matter I was getting from it.

I tried going to mozilla's site but nothing helps. I can't go to the Firefox troubleshooter because for me to use it, I need to gain access to it, and it refusing to show on screen doesn't help.

If this sounds familiar, any suggestions outside of deleting their profile again and starting anew?