If you go to about:profiles in Firefox, do you see multiple profiles listed? It's possible that Firefox accidentally created a new blank profile that is now the default one.

See the Determine if Firefox has created a new profile section of Recover lost or missing Bookmarks for more information

Hope this helps.

ken said

After my pc got suspend by electric power

Do you mean you had a blackout/brownout/power outage?

When a computer loses power without closing down first, files can become corrupted.

Perform a System File Check to fix corrupted system files

Win 7, 8, 10, Vista: https://support.microsoft.com/en-us/kb/929833 Win XP: https://answers.microsoft.com/en-us/windows/forum/all/windows-xp-scan-and-fix-disk-errors/6fe2827a-4be6-4bc1-8083-5139b5aa3a3d

Wiki - Windows 10 System File Check http://answers.microsoft.com/en-us/windows/wiki/windows_10-update/system-file-check-sfc-scan-and-repair-system-files/bc609315-da1f-4775-812c-695b60477a93

Look on your desktop. Do you see a folder called; Old Firefox? Look inside. Look for the folder with the latest creation date.

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

https://support.mozilla.org/en-US/kb/back-and-restore-information-firefox-profiles

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

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

http://kb.mozillazine.org/Profile_folder_-_Firefox#Navigating_to_the_profile_folder

https://support.mozilla.org/en-US/kb/profile-manager-create-and-remove-firefox-profiles

https://support.mozilla.org/en-US/kb/back-and-restore-information-firefox-profiles

Type about:profiles<enter> in the address bar. How many profiles are listed? How many should be there? Also, open the folder in your file explorer.

I think your answer can solve it. The fisrt time it happened, I saw the "Old FireFox" in Desktop. But this time, I can't find it. So that mean I can't recovery anything ?

Did you check out the about:profiles suggestion?

ya I have checked. Have 2 profile:

• The first have nothing
• The second have my account logged, but it doesn't have any thing about my's extension setup

Sorry, but it looks like the data was lost.

Back up and restore information in Firefox profiles.{web link} I use an add-on that makes backups of my user profile, Just In Case. Unfortunately, it is not compatible with the current Firefox.

Every now and then, open the profile folder and create a copy of the current profile as is to another location on your hard drive. This way you will have a backup.

If you do this each day, you will not lose much data. This should be done with Firefox Closed.

Note: In case you need to restore from these backups, you may need to overwrite old or corrupted files.

Ok thanks for your help.

Did you look in the default location for possible profiles that aren't registered in profiles.ini ?

See "Profile was moved or renamed":

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