Can you find an Add-On that was deleted?
Had a problem with an add-on that resulted in all add-ons being deleted. As I wasn't sure what caused the problem, I deleted Firefox and reinstalled it. After the reinstall no add-ons were present. I added back 1 that I could remember, but the second one is gone. I do not remember the name of the add-on but found it very useful in managing pop-ups, videos automatically playing, etc. Would really like to get it back. By any chance, does Firefox store add-on information so that I might be able to find the missing add-on?
You can look at a utility to browse System Restore points and see if you can locate an older extensions.json file.
You can use the button on the "Help -> Troubleshooting Information" (about:support) page to go to the current Firefox profile folder or use the about:profiles page.
- Help -> Troubleshooting Information -> Profile Folder/Directory:
Windows: Open Folder; Linux: Open Directory; Mac: Show in Finder
You can use this tool to inspect this file. https://www.jeffersonscher.com/ffu/extensionsjson.html