Are you running in permanent private browsing mode?

Make sure that you do not run Firefox in (permanent) Private Browsing mode.

• https://support.mozilla.org/kb/Private+Browsing

• Tools > Options > Privacy > Firefox will: "Use custom settings for history"
• Deselect: [ ] "Always use private browsing mode"

Okay I finally figured it out. Thank you the-edmeister and cor-el. Odd how I've always had the privacy set to "Never Remember History" and there was never a problem. What changed? Now I guess I'll have to manually clear my history before closing the browser. Bummer.

i found this via google, and checked and my box is unchecked, but still no themes work for me!!

Hi metalman228

You can check for problems with the localstore.rdf file.

• http://kb.mozillazine.org/Corrupt_localstore.rdf

Try to rename or delete the prefs.js file and possible numbered prefs-##.js files and a possible user.js file to reset all prefs to the default values.

• http://kb.mozillazine.org/Preferences_not_saved
• http://kb.mozillazine.org/Resetting_preferences

Create a new profile as a test to check if your current profile is causing the problems.

See "Creating a profile":

• https://support.mozilla.org/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 some files from an existing profile to the new profile, but be careful not to copy corrupted files.

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

What has private browsing mode or clearing history or not got to do with themes?

I followed the first item in your list. Removing/renaming the corrupt localstore.rdf file from your profile. I did this and it reset FF. Removed the bookmarks, settings and all passwords, and the plugins disappeared . Plus i could not connect to the internet. Please see screenshot.

I had to remove/reinstall FF, so i installed 20.0.0. I had to import my bookmarsks from my Backup .Json file None of my passwords could be recovered, so this will be a very time consuming process that did not solve my problem.

I am afraid to try anything else your recommending. I agree with what finitarry wrote: "What has private browsing mode or clearing history or not got to do with themes?"

If there is a theme you really want to use, downloading the .jar or .xpi file, then extracting the install.rdf file, editing the max version for the target application and making it larger, then saving and putting that file back into the archive, then installing that theme from the modified archive should work. It does for me.

You should always be careful with bumping the maxVersion of a theme that refuses to install.
A theme that isn't working properly can have serious impact on the functioning of Firefox.

The error that shows in your screenshot can be caused by a problem with the secmod.db file or the cer8.db file.

• https://support.mozilla.org/kb/Could+not+initialize+the+browser+security+component

You can use this button to go to the Firefox profile folder:

• Help > Troubleshooting Information > Profile Directory: Show Folder

Well finitarry, i like your solution, but that is honestly way beyond my capability's.

I think with so many people having this issue that have posted to the mozzila forums, a general solution will be found at some point.

this error was caused directly from removing the localstore.rdf file as outlined in your response to me yesterday.

i did not know it would do that.

The only effect that removing localstore.rdf should have is resetting the toolbar customization (there is more persistent data stored in the file)

• http://kb.mozillazine.org/localstore.rdf

Current Firefox version disable a possible persona and theme to make it more noticeable that you are in PB mode.
If PB mode didn't apply then yo can have other files that were corrupted, but it is hard to tell which files in such a case.

That may be true, but I am just relaying back the result of performing that modification.

To fix my FF i had to remove FF, including all the personal data, and then remove all the profile files leftover. I then reinstalled FF and started with a brand new profile, but the themes will still not work.