hello. can you please try the alternatives given in this help article: https://support.mozilla.org/kb/Safe+Mode Also you Profile folder shows the presence of user.js file. but User.js file “does not exist by default. if you haven't created it yourself in the first place or aren't sure what has created it, then the user.js file shouldn't be there at all. you can go ahead and delete the file - it won't affect your stored bookmarks or other personal data... see this article: [[How to fix preferences that won't save ]]