If you're having problems with Firefox, refreshing it can help. The Refresh feature is available on Firefox for desktop or laptop computers. A refresh can fix many issues by restoring Firefox to its default state while saving your essential information like bookmarks, passwords, and open tabs.
All of your Firefox settings and personal information are stored in a profile folder. The refresh feature works by creating a new profile folder for you while saving your important data.
Add-ons which are normally stored inside the Firefox profile folder, such as extensions and themes, will be removed. Add-ons stored in other locations, such as plugins, will not be removed but any modified preferences (such as plugins you have disabled) will be reset.