Start Firefox in Safe Mode to check if one of the extensions ("3-bar" menu button or Tools -> Add-ons -> Extensions) or if hardware acceleration is is causing the problem.

• switch to the DEFAULT theme: "3-bar" menu button or Tools -> Add-ons -> Appearance
• do NOT click the "Refresh Firefox" button on the Safe Mode start window

• https://support.mozilla.org/en-US/kb/troubleshoot-firefox-issues-using-safe-mode
• https://support.mozilla.org/en-US/kb/troubleshoot-extensions-themes-to-fix-problems

I have done the below together:

• Disable all themes
• Disable all plugins
• Disable all extensions
• Launched in safe mode

The same thing continues to happen.

Hello panda360,

Just to make sure, would you check this :

Type in the address bar about:config and press Enter (promise to be careful, if asked)

Type in the search bar security.ask

and look for the preference security.ask_for_password

Make sure its value is set to 0 (zero)

If you had to change the value (0 = default), then close and restart Firefox.

Any luck  ?

It is indeed set to 0 (zero).

I have also tried deleting pages that require passwords from my bookmark bar as well.

panda360 said

It is indeed set to 0 (zero). I have also tried deleting pages that require passwords from my bookmark bar as well.

Bummer  ! (must admit that it was a mere stab in the dark)

Would you take a look at this thread please :

https://www.reddit.com/r/firefox/comments/7qq43l/annoying_enter_master_password_at_every_startup/

You shouldn't have to do that, but for now, till someone comes up with a better solution ?

You can check for problems with preferences.

• delete possible user.js and numbered prefs-##.js files and rename/remove the prefs.js file to reset all prefs to the default value including prefs set via user.js and prefs that are no longer supported in current Firefox releases
• http://kb.mozillazine.org/preferences_not_saved
• http://kb.mozillazine.org/resetting_preferences

You can create a new profile to test if your current profile is causing the problem.

See "Creating a profile":

• https://support.mozilla.org/en-US/kb/profile-manager-create-and-remove-firefox-profiles
• http://kb.mozillazine.org/Standard_diagnostic_-_Firefox#Profile_issues

If the new profile works then you can transfer files from a previously used profile to the new profile, but be cautious not to copy corrupted files to avoid carrying over problems.

• http://kb.mozillazine.org/Transferring_data_to_a_new_profile_-_Firefox

If this all doesn't help then try a clean reinstall and make sure to remove the Firefox program folder.

• https://www.mozilla.org/en-US/firefox/all/

I don't know if I am looking at the right thing...

So under a folder called defaults, there is a pref folder containing 2 .js files.

• channel-prefs.js
• kl_prefs_62fbb8f7_c917_4cf7_957a_aad2b8fa768c.js

Deleting them does not help, as kl_prefs_62fbb8f7_c917_4cf7_957a_aad2b8fa768c.js is always recreated. However if I delete the entire pref folder, the prompt stops happening.

Is this a helpful lead?