On a Mac, Firefox was running slowly. A message at the bottom of the screen had a suggestion which I followed. Now when I try to re-open Firefox, I get an error message saying "Profile missing. Your Firefox profile cannot be loaded. It may be missing or inaccesible." I have deleted and re-downloaded Firefox three times, and shut down the Mac multiple times. I combed through this support forum and found the info re: the hidden Library, and the profile.ini file. I don't have a profile.ini file there, just a page. Help! I've been a loyal Firefox browser user, but am now working in Chrome (and I have to say that it's speeding along).