You can check if you have an orphaned profile that isn't registered in profiles.ini and that doesn't show in the Firefox Profile Manager. You can check that by opening the current profile folder via the about:profiles page and go up one level (..) to see if there are unlisted profiles present. If you have found an orphaned profile then you may want to recover some personal data or restore his profile.

• https://support.mozilla.org/en-US/kb/recovering-important-data-from-an-old-profile

You can recover an orphaned profile via these steps:

• use the Profile Manager to create a new profile
  https://support.mozilla.org/en-US/kb/profile-manager-create-and-remove-firefox-profiles
• click "Choose Folder" in the Profile Manager
• browse to the location of this profile to register this profile in the Profile Manager and use this profile

See "Profile was moved or renamed":

• https://support.mozilla.org/en-US/kb/how-run-firefox-when-profile-missing-inaccessible

Note that you should never use "Choose Folder" to specify a folder that already contains files that do not belong to Firefox. Only use "Choose Folder" to recover an profile that isn't listed in the Profile Manager.

If you happened to close Firefox before the Refresh procedure was complete, like you thought Firefox was 'hung' and then closed or restarted Firefox or your PC - your data is gone. I did that the first time that I used Refresh. Fortunately I had back up that Profile before running the Refresh procedure; did exactly the same thing the next time a half-hour later, just to reassure myself my 'SWAG' was valid. I waited 5 minutes and then killed the firefox.exe process in the Windows Task Manager as I did the first time, and had exactly the same result.

That happened to me me on a one year old PC with a 3.3 GHZ 4-core processor and 4 GB of RAM on Windows7 when it seemed to take over 5 minutes the first time I used Refresh on a Profile that I had barely used (IOW very little data to deal with), and I thought that Firefox was 'hung' so I closed it. Voila' no Old Firefox Data folder on the Desktop AND my Profile was empty; nothing saved that should have been saved and as expected the data that would be cleared was gone, too.

It seems that Firefox Profile data is held in RAM while the Refresh procedure is running ; so as soon as Firefox is closed that data held in RAM goes 'poof' - it's gone. Sacrificed to the 'tron gods'.

IMO, there oughta be a "progress meter" to display how far along the Refresh process is at any time while it is running. As fast as my PC is, in comparison to the 8 year old PC that I replaced, I can't comprehend why that Refresh process takes so long. And I thing it is 'bad form' to not give the user an indicator; my feeling as an almost a 16 year user - I started with Phoenix 0.3 back in Aug 2002.