Hello

You cannot run Firefox without a profile. A profile isn't a social media account or a login, its simply the folder on your hard drive where Firefox saves your personal information such as bookmarks, passwords and user preferences in a set of files called your profile, which is stored in a separate location from the Firefox program files. If you delete your profile, you delete your data.

That yellow triangle maybe is the "Sync" Warning (you can share a printscreen).

Please select the answer that solves the problem. This will help other users with similar problems find the solution.