I had the same issue just today actually when I read your thread. I don't normally have the Top Sites section displayed on the Firefox homepage, so I don't know how long this was an issue for.

I think that reinstalling Firefox from the Firefox website should do the trick to fix it.

If you care to know how I actually fixed my issue, it's a little different. I run and test the newer versions of Firefox with a test profile, so I also have Firefox Nightly installed on my system. The issue actually was fixed when I accidentally opened by regular Firefox profile in Firefox Nightly.

Pinned tabs are stored in a pref on the about:config page.

• browser.newtabpage.pinned = ;[{"url":"https://support.mozilla.org","label":"SUMO"}]

You can check the pref to see if there is a problem with it.

You can open the about:config page via the location/address bar. You can accept the warning and click "I accept the risk!" to continue.

• http://kb.mozillazine.org/about:config

Changes made manually on the about:newtab page are stored in prefs that you can find on the about:config page.

• browser.newtabpage.pinned stores websites that you have pinned to a tile.
• browser.newtabpage.blocked stores websites that you have removed by clicking the Dismiss (X) button in a tile.

Thanks for this, but on the browser.newtabpage.pinned value I can see all the web addresses for the attempts I have made but nothing is actually pinned on Top Sites. I don't know what else to look for in about:config, can you provide any further help? Thanks.

If you are trying to add a new Top Site to the Firefox New Tab page, see the Customize your Firefox New Tab page article under Add a Top Site (viewable in Firefox 60 and above) for detailed steps.

If you see blank tiles or have other issues with Top Sites on the New Tab page, see if it works when you restart Firefox with Add-ons disabled, in Firefox Safe Mode: Diagnose Firefox issues using Troubleshoot Mode

Try to reset browser.newtabpage.pinned to remove all your attempts and start with a fresh pinned list. Also reset browser.newtabpage.blocked is case there is some interference.

You can also try to toggle browser.newtabpage.enabled off/on to reinitialize (restart Firefox in between with the pref set to false).

Cor-el, thanks for the tips but none of them worked! I haven't and don't want to try in Firefox safe mode. Is there anything else I can do? One of the forum answers said my Firefox profile could be corrupted?

Gooner321 said

I haven't and don't want to try in Firefox safe mode.

Is there a specific reason why you don't want to try Firefox Safe Mode? Safe Mode is only temporary and doesn't make any permanent changes to your Firefox settings. It would help eliminate the possibility that it's an issue with your Firefox settings or addons.

Are there any messages in the Browser Console about the new tab page?

• https://developer.mozilla.org/en/Tools/Browser_Console

Cor-el, I just opened it in safe-mode:

1528479323366 addons.xpi WARN Expected add-on tls13-version-fallback-rollout-bug1462099@mozilla.org is missing from the system add-on location. Error: Error(s) encountered during statement execution: database disk image is malformed Sqlite.jsm:807:25 NS_ERROR_XPC_GS_RETURNED_FAILURE: Component returned failure code: 0x80570016 (NS_ERROR_XPC_GS_RETURNED_FAILURE) [nsIJSCID.getService] nsUrlClassifierListManager.js:65 JQMIGRATE: Logging is active common-min.4d86858ec129.js:6:5685 unreachable code after return statement js:69:1216 Cross-Origin Request Blocked: The Same Origin Policy disallows reading the remote resource at https://location.services.mozilla.com/v1/country?key=fa6d7fc9-e091-4be1-b6c1-5ada5815ae9d. (Reason: missing token ‘x-csrftoken’ in CORS header ‘Access-Control-Allow-Headers’ from CORS preflight channel). (unknown) Error: Error retrieving geoip data common-min.4d86858ec129.js:10:26804 Error: Error(s) encountered during statement execution: database disk image is malformed Sqlite.jsm:807:25 Failed to fetch the data for an item Error: Error(s) encountered during statement execution: database disk image is malformed PlacesUtils.jsm:1827 Sync encountered an error - see about:sync-log for the log file. policies.js:804

If you use Sync then best is to disconnect Sync temporarily during troubleshooting.

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

• use "Verify Integrity" on the "Help -> Troubleshooting Information" (about:support) page

See also:

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

If "Verify Integrity" on the "Help -> Troubleshooting Information" (about:support) page cannot repair places.sqlite then remove all places.sqlite files in the Firefox profile folder. Firefox will rebuild places.sqlite and restore the bookmarks from a 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

Sorry Cor-el but this is above my knowledge. I don't want to rummage around and ruin something. I suspect there is a problem with my profile. All problems started when I tried to reboot after a recent 1gb mac os security update. My tech guy had to re-install everything from my Time Machine back-up and re do the security update. Ever since then I can't get to add any Top Sites.