https://support.mozilla.org/en-US/kb/how-to-fix-preferences-wont-save

Note: Some software, like Advanced SystemCare with Surfing Protection, can protect files in the Firefox profile folder against changes. If you have such software then check the settings or uninstall this software.

Thanks Fred, but I don't have that and there was no recent change on the computer software.

Can you check whether your Bookmarks Toolbar items are still in your bookmarks database by checking one of these other places:

• Bookmarks drop-down menu, Bookmarks Toolbar fly-out list
• Bookmarks Sidebar -- Ctrl+b -- Bookmarks Toolbar category
• Library window -- Ctrl+Shift+b (or "Show All Bookmark") -- Bookmarks Toolbar category

Did Firefox do anything strange at startup recently? Examples would be saying that your profile is missing or unavailable, or saying that Firefox is starting slowly and you can speed it up by resetting some settings, or any other unexpected messages?

Thank you jscher2000. As I wrote on my starting post, the bookmark files are on their directory and I can even open them on the browser. I'll keep trying other things. I use a second profile and keep the original from installation virgin. The issue is not there, but it is not the same profile.

Straydog said

As I wrote on my starting post, the files are on their directory and I can even open them on the browser.

I'm not sure I understand: when you say you can open files on the browser, do you mean your Bookmarks Toolbar items show up in the locations I mentioned or not?

When you are using Customize, do you see the "Bookmarks Toolbar Items" on the Bookmarks Toolbar? I am attaching a screenshot showing what that looks like. If necessary, you can use the "Restore Defaults" button to return the toolbar layout to the initial setup. (For reference: Customize Firefox controls, buttons and toolbars)

Make sure toolbars like the "Bookmarks Toolbar" are visible. Open the Customize window and set what toolbars (Show/Hide Toolbars) and toolbar items to display.

• Right-click empty toolbar area -> Customize
• "3-bar" menu button -> Customize
• View -> Toolbars
  You can tap the Alt key or press F10 to show the Menu Bar

• check that "Bookmarks Toolbar Items" is on the Bookmarks Toolbar
• if "Bookmarks Toolbar Items" is not on the Bookmarks Toolbar then drag it back from the Customize palette to the Customize window to the Bookmarks Toolbar

• if missing items are in the Customize palette then drag them back from the Customize window to the toolbar
• if you do not see an item on a toolbar and in the Customize palette then click the Restore Defaults button in the Customize palette window to restore the default toolbar set.

You can check for problems with the places.sqlite database (bookmarks and history) in the Firefox profile folder.

• https://addons.mozilla.org/firefox/addon/places-maintenance/

See also:

• http://kb.mozillazine.org/Bookmarks_history_and_toolbar_buttons_not_working_-_Firefox
• https://support.mozilla.org/en-US/kb/Bookmarks+not+saved#w_fix-the-bookmarks-file

If the Places Maintenance extension can't repair the places.sqlite database then remove all places.sqlite file(s) in the Firefox profile folder to make Firefox rebuild the places.sqlite database from the most recent JSON backup in the bookmarkbackups folder.

• keep a backup copy of places.sqlite in case a new places.sqlite database has to be created
• http://kb.mozillazine.org/Unable_to_process_the_backup_file_-_Firefox

You can use the button on the "Help -> Troubleshooting Information" (about:support) page to go to the current Firefox profile folder or use the about:profiles page.

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

jscher2000 said

I'm not sure I understand: when you say you can open files on the browser, do you mean your Bookmarks Toolbar items show up in the locations I mentioned or not?

I mean the profile files at profile.xxx\bookmarkbackups\

jscher2000 said

When you are using Customize, do you see the "Bookmarks Toolbar Items" on the Bookmarks Toolbar? . If necessary, you can use the "Restore Defaults" button to return the toolbar layout to the initial setup.

Yes, I can always see an empty toolbar (normal on customize window, but not otherwise). Unfortunately, "Restore Defaults" restores the icons, but not the toolbar.

______ Please note: The bookmarks toolbar is 'not missing'. It is empty. ¯¯¯¯¯¯

Thanks cor-el. I checked al your advices and links, but couldn't fix it. That is why I have taken so long to reply. It must be something stupid making this happen. The missing items are not on the customize window. That is why I have taken so long to reply.

Let me try to be precise:

• The Bookmarks Toolbar is displayed below the address bar, but does not show any bookmarks => TRUE
• In Customize, the "Bookmarks Toolbar Items" control which is what actually shows the bookmarks is in its default location at the left end of the Bookmarks Toolbar => TRUE
• In the Library window, when you click Bookmarks Toolbar in the left column, the right pane lists the expected contents of the toolbar => TRUE or FALSE?

Do you see the "Bookmarks Toolbar Items" positioned on the Bookmarks Toolbar when you are in customization mode? This is different than seeing an empty toolbar. "Bookmarks Toolbar Items" represents the container that shows the bookmarks in regular mode.

If you see this container in customization mode, but you do not see bookmarks that are in the Bookmarks Toolbar folder then it is likely that there is a problem with the places.sqlite database or an extension or external software is causing problems.

Eureka! After all this searching and trouble I finally found the culprit. It is the FT DeepDark Theme. When I changed to the default theme and restarted nearly all became normal again as before. I had already done this before without any result, but now it worked. Only the "Show your bookmarks" icon was still not there, but came back when I clicked the "Restore Defaults" button on the customization menu window. It also did not work with the other theme. I searched what was wrong for two days now, before asking in here. I was using the bookmarks on my latest saved HTML file, very awkward, really.

What I completely fail to understand is why that happened now when I have been using this theme for about one month.

I think my other problem should be posted on a different section.

Sorry, I couldn't reply to you two latest posts because I was writing mine. It is absurd that a theme downloaded from the Firefox add-ons pages can make all this trouble,

To answer you, no the bookmarks toolbar was there, but empty. I used the button on customize window to hi and unhide it. It worked but it was always empty. The reset feature worked with the icons, but not on the toolbar.

I am very thankful to both for you effort and kindness on trying to help.