https://support.mozilla.org/en-US/kb/how-to-fix-preferences-wont-save

Note: Some software, like Advanced SystemCare with Surfing Protection, can protect files in the Firefox profile folder against changes. If you have such software then check the settings or uninstall this software.

I have a similar issue - but only when a Firefox Upgrade is applied.

My customization is maintained when I restart my Windows Desktop PC - but whenever Firefox is automatically updated, it reverts to defaults and loses all my customization, hence I have stopped updating until a solution is found or a work-round is advised. I am amazed more people are not raising this issue.

StellarX Others have had your same issue. This has been resulted in 1) the profile being refreshed, and 2) a new profile was created.

1) 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

2) 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 profile folder in your file explorer.

Hi and thank you very much for taking time to reply and advise.

There is no 'Old Firefox' on my Desktop, nor can I locate a folder with that name on a search of my entire PC.

When I enter 'about:profiles' in my Firebox browser search bar, it shows a panel advising:

Default Profile: Yes. Root Directory: A 'Roaming' Filepath is specified. Local Directory: A 'Local' Filepath is specified.

I'll read in detail all the links you supplied to ascertain what to do to fix my problem. Thank you once again for your kind guidance.

Please go to the top of any support.mozilla.org web page and use the Get Community Support link: https://support.mozilla.org/en-US/questions/new

Select the product for what the problem is (Firefox or whatever). Now select the category for the problem. At the bottom is Other.

Describe the problem in brief (one line). Then press <enter>. The website will display any prior posts that might help you. If nothing on the list can help, at the bottom press the button; None Of These Solve My Problem.

Now enter all the relative information on the problem. At the bottom of this, you can Add Images.

Under this is Troubleshooting Information. Please press the Share Data button. This will let us look at your system details. No Personal Information Is Collected.

oblivivion said

The "Customize..." feature lets you move around icons and other things in Firefox's interface. When you apply these customizations, they *should* be saved in your browser, so that the next time you open Firefox, you have the same customizations you applied earlier. Whenever I restart my computer, these settings are completely reset to their defaults and I have to apply the same customizations every time. How do I fix this???

To oblivivion: Did this reply by FredMcD solve your issue? If so, please mark it as solving the problem. If you need more help with this issue, please post back.

To StellarX: Please ask your own question as FredMcD advised if you need help, even though you may have a similar issue. The way this forum works, the original poster "owns" the thread and all replies should be aimed to help that person. See Mozilla Support rules and guidelines. For other support resources, see Get community support.

I will respond to advise if the issue is resolved as soon as I have had chance to read, and if necessary act on, the guidance in all the links supplied. I have not yet had chance to do this but will do so over the coming weekend.