Hi drakekoefoed, I think the tune-up was a Refresh, as described in this article: [[Refresh Firefox - reset add-ons and settings]]. Assuming that is what happened, your old Firefox profile folder is on your desktop inside a folder named '''Old Firefox Data''' -- can you find that? Assuming you have Old Firefox Data, double-click into that and then into your old profile folder. Resize the Windows Explorer window so you can see Firefox behind it. Then drag '''extensions.json''' over to Firefox and drop it into the web content area to view its contents. After a few moments, Firefox will display a structured view of the file. If you use Find (Ctrl+f) to look for MP3, you should be able to find the name of the missing add-on and then relocate it on the Add-ons site.