I’ve been using FF for years and I use at home. I’ve never had problems until this new download.
I did a troubleshoot and it said FF was incompatible with win 8.1
The Firefox troubleshooter said that? Firefox runs in its own encapsulated little environment. It has its own cookie store, cache, bookmarks, even certificate repository.
In Firefox, go to Help > Troubleshooting Information and click the “Reset” button in the top right corner. You might have an add-on or extension that’s gone haywire.