This may happen due to permantly using Private Browsing mode, which equals setting it to Never remember history. Would that apply? The message should only be displayed when a Firefox profile has not been used for 60 days.

Nevertheless, there is an existing bug report for this issue which may apply to your setup. A related bug is also interesting.

Try opening about:config, enter app.update.enabled and set it to false (by doubleclicking it or using right-click > Toggle) if set to true. This is mentioned as a workaround in the second bug.

Please lest us know if this helps or if you need further assistance.

the message might be a result of some parts of your firefox profile being write-protected. what you could try to do to get rid of the error message, you could try deleting the files lock and/or .parentlock within the firefox profile folder.

alternatively it should be possible to work around the issue like this: enter about:config into the firefox address bar (confirm the info message in case it shows up) & right-click somewhere to create a new boolean preference with the name browser.disableResetPrompt set to true.

Thank you for the quick replies. After reading your answers and the provided links I understood the reason. The browser calculates the 60 days period using the modification time of .parentlock file from the profile directory. I use live GNU/Linux system, and save the changes of Firefox profile directory only when I change something (like a setting). So, my .parentlock file was older than 60 days. But creating the browser.disableResetPrompt boolean (true) preference solved the problem.

Otherwise, I deem this feature totally useless and even annoying. Why it is supposed that I want to change the browser settings even if I did not started it for a while...? In the case I want to change something, then I change it. And this does not depend on how long time has passed...

See also:

• https://www.ghacks.net/2013/10/27/reset-firefox-notification-appears-started-firefox-61-days/
• Bug 955950 - Preference to disable/select the number of days until recommending a reset [29]

cor-eI, I have read your link and agree with the opinion of "Now You See It, Now You Don't". Yes, besides the settings also the add-ons go away with the refresh. Really, very "useful" feature!

To be clear: I have no problem with refresh if the user really needs it. May be a situation when it solves the problems. But this reset prompt has no any connection with such a case.