- missing Windows 10 title bar [solution found, 10-years-old]
- hard to see tabs - again a very old issue 
  specifically they all just run on, they don't have a /¯¯¯¯¯\ look, 
  really hard on these old eys!  
- no refresh button at right of URL - again, very old issue

After powering off my locked-up Windows 10 PC, Firefox came back looking very different. I believe it showed some sort of indication I was new to Firefox, i.e. a welcome screen, or something, sorry, I forget. The "issues" I found were: - missing Windows 10 title bar [solution found, 10-years-old] - hard to see tabs - again a very old issue specifically they all just run on, they don't have a /¯¯¯¯¯\ look, really hard on these old eys! - no refresh button at right of URL - again, very old issue SO I have to think something got corrupted, but in searching, I find references to the rdf file, it being deprecated, etc. I followed the directions for "reset Firefox" and reinstalled my add-ons, then manually [x]'ed the "title bar" option to at least get THAT back. Thank you very much for your thoughts and solution. Ward Christensen, inventor of "Xmodem" and "Bulletin Board Systems" (BBSs). Yes, I'm old - 75.