If you have user.js file then you should see a section about this file on the "Help > Troubleshooting Information" page.

• https://support.mozilla.org/kb/Using+the+Troubleshooting+Information+page

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

• Help > Troubleshooting Information > Profile Directory: Show Folder (Linux: Open Directory; Mac: Show in Finder)
• http://kb.mozillazine.org/Profile_folder_-_Firefox

There is software like Advanced SystemCare with its Surfing Protection feature that can protect files in the Firefox profile folder against changes. If you have such software then check the settings or uninstall this software.

If you do not keep changes after a restart or otherwise have problems with preferences, see:

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

Do you mean the tiles on the new tab page, which are added based on your history, but which you can replace with bookmarked sites?

If the automatically generated tiles vanish, it could be because history is getting cleared at shutdown.

If tiles you added manually are being removed, or if tiles you deleted come back, then most likely the prefs.js file is getting deleted or overwritten. Something like Advanced SystemCare or another utility/security/privacy program with a browser cleanup or settings protection feature could be the culprit.

bitternloco said

I am trying to get my Tiles to stay permanently - they now disappear after each session but I don't know why.Having looked at similar questions put by others it appears that I should delete user.js but I don't really know what that is or how to find it. Forgive me,I am not very computer savvy and I struggle with jargon.Can you help me please? Thanks,David.

jscher2000 said

Do you mean the tiles on the new tab page, which are added based on your history, but which you can replace with bookmarked sites? If the automatically generated tiles vanish, it could be because history is getting cleared at shutdown. If tiles you added manually are being removed, or if tiles you deleted come back, then most likely the prefs.js file is getting deleted or overwritten. Something like Advanced SystemCare or another utility/security/privacy program with a browser cleanup or settings protection feature could be the culprit.

Thanks for the information supplied.As I said I am not computer savvy and I am having difficulty in following the instructions supplied by cor-el which will be entirely due to my lack of computer knowledge.

I would,however, like to reply to the message from jscher2000.I do mean the tiles on the tab page based upon my history as I found that feature very useful when opening up firefox each day.They are now disappearing at shutdown and my question is how can I stop this from happening.Should I try to find user.js and pref.js and delete them?

Thanks for your help on this.

Which kind of tiles are disappearing?

If history tiles are disappearing, check to make sure that Firefox is not set to clear history at shutdown. That would be set up on the Options page, Privacy panel:

"3-bar" menu button (or tools menu) > Options > Privacy

If the selector says "Firefox will: Remember history" then probably you do not have Firefox set to clear history at shutdown.

If the selector says "Firefox will: Use custom settings for history" then check whether "Clear history when Firefox closes" has been turned on. If so, you could turn that off completely, or click the Settings button to select categories of history to clear and make sure browsing history is not selected.

If the selector says "Firefox will: Never remember history" then Firefox uses automatic private browsing and no history is kept between sessions.

Do any of those explain what is going on?

To answer your question, history tiles should not be affected by prefs.js or user.js, so I wouldn't look for those at the moment.

Thank you jscher2000 - you have solved my problem! I checked the selector and it was showing the 2nd of the 3 possibilities that you listed.I followed your very clear instructions and bingo! - my tiles are back upon reopening firefox.

I am very grateful to you.

Regards,David.