Hi Wrubel, You wouldn't happen to be in permanent Private Browsing mode ?

RobertJ said

Hi Wrubel, You wouldn't happen to be in permanent Private Browsing mode ?

Unfortunately, no. FF runs in regular mode. But actually, if I turn option to run in pernament Private Browsing on, it is being turned off after re-opening browser as well.

Private Browsing only lasts until you turn it off or close the browser.

You may be in Private Browsing mode or told Firefox not to remember.

Type about:preferences#privacy<enter> in the address bar. The button next to History, select Use Custom Settings.

Turn off Always Use Private Browsing Mode Turn on Remember My Browsing And Download History At the bottom of the page, turn on Clear History When Firefox Closes. At the far right, press the Settings button. Turn on ONLY Cache and Form And Search History leaving the others off.

FredMcD said

Private Browsing only lasts until you turn it off or close the browser. You may be in Private Browsing mode or told Firefox not to remember. Type about:preferences#privacy<enter> in the address bar. The button next to History, select Use Custom Settings. Turn off Always Use Private Browsing Mode Turn on Remember My Browsing And Download History At the bottom of the page, turn on Clear History When Firefox Closes. At the far right, press the Settings button. Turn on ONLY Cache and Form And Search History leaving the others off.

I follwed the instructions. After restarting firefox all data was cleared and settings were back to previous ones. It seems that it also changed start page to blank. The settings browser keep getting back to are:

"Awlays use private browsing mode" - off "Clear history when Firefox Xloses" - on, with all settings on

Additionaly, I ran antivirus and malware scan. It found nothing.

Some other things to check:

Some security software includes a "Privacy Cleanup" feature.

Some third-party toolbars and add-ons change Firefox's home page and search settings.

A user.js file is overriding Firefox settings.

Locked or Corrupt prefs.js file.

More details are in How to fix preferences that won't save.

Suggestion: Save Refresh as a last resort.

RobertJ said

Some other things to check: Some security software includes a "Privacy Cleanup" feature. Some third-party toolbars and add-ons change Firefox's home page and search settings. A user.js file is overriding Firefox settings. Locked or Corrupt prefs.js file. More details are in How to fix preferences that won't save. Suggestion: Save Refresh as a last resort.

RobertJ, you are a life-saver! :D Editing the user.js file resolved the issue. Thanks a lot!

I'm glad we could track it down. Good work!

Browse Safe!