Explain in detail what it is you did.

If you have sync, and there is a problem anywhere, Shut Down Sync Immediately On All Devices to prevent the problem from spreading. Type https://accounts.firefox.com/settings<enter> in the address bar. Once the problem is fixed, perform the same repair on all computers/profiles before using sync again.

[v57+] Places Maintenance is built into Firefox.

Type about:support<enter> in the address bar.

You will find Places Database near the bottom. Press the Verify Integrity button.

If any errors are reported: https://support.mozilla.org/en-US/kb/fix-bookmarks-and-history-will-not-be-functional

The places.sqlite file contains your History and Bookmarks. And it looks like it is corrupted.

Type about:support<enter> in the address bar.

Under the page logo on the left side, you will see Application Basics. Under this find Profile Folder. To its right press the button Show Folder. This will open your file browser to the current Firefox profile. Now Close Firefox.

Locate the above file. Then rename or delete it. Restart Firefox. The browser should then create a new place.sqlite and recover your bookmarks from the backup files.

Note: Your history is not backed up and will be lost.

Thank you for your reply. I had already listed in my original post the troubleshooting methods I had tried. What other information were you asking for when you said, "Explain in detail what it is you did."? I'll be happy to tell you once I know what you're looking for.

As mentioned in my original post, I had already tried deleting the places.sqlite file, and that had no effect on my issue.

I am not using Sync. I only use Firefox on one device.

I clicked the "Verify Integrity" button for the Places Database, and here is what I got:

> Task: checkIntegrity + The places.sqlite database is sane + The favicons.sqlite database is sane > Task: invalidateCaches + The caches have been invalidated > Task: checkCoherence + The database is coherent > Task: expire + Database cleaned up > Task: originFrecencyStats + Recalculated origin frecency stats > Task: vacuum + Initial database size is 5120KiB + The database has been vacuumed + Final database size is 5120KiB > Task: stats + Places.sqlite size is 5120KiB + Favicons.sqlite size is 448KiB + pragma_user_version is 58 + pragma_page_size is 32768 + pragma_cache_size is -2048 + pragma_journal_mode is wal + pragma_synchronous is 1 + History can store a maximum of 112348 unique pages + Table moz_origins has 43 records + Table moz_places has 92 records + Table moz_historyvisits has 48 records + Table moz_inputhistory has 0 records + Table moz_bookmarks has 112 records + Table moz_bookmarks_deleted has 0 records + Table moz_keywords has 0 records + Table sqlite_sequence has 1 records + Table moz_anno_attributes has 0 records + Table moz_annos has 0 records + Table moz_items_annos has 0 records + Table moz_meta has 7 records + Table moz_places_metadata has 0 records + Table moz_places_metadata_search_queries has 0 records + Table moz_places_metadata_snapshots has 0 records + Table moz_places_metadata_snapshots_extra has 0 records + Table moz_places_metadata_snapshots_groups has 0 records + Table moz_places_metadata_groups_to_snapshots has 0 records + Table sqlite_stat1 has 15 records + Pages sequentiality: 100 + sqlite_schema: 32KiB (2.2%), 25.5% eff. + moz_origins: 32KiB (2.2%), 4.8% eff. + sqlite_autoindex_moz_origins_1: 32KiB (2.2%), 4.4% eff. + moz_places: 32KiB (2.2%), 49.8% eff. + moz_historyvisits: 32KiB (2.2%), 3.1% eff. + moz_inputhistory: 32KiB (2.2%), 0% eff. + sqlite_autoindex_moz_inputhistory_1: 32KiB (2.2%), 0% eff. + moz_bookmarks: 32KiB (2.2%), 27.3% eff. + moz_bookmarks_deleted: 32KiB (2.2%), 0% eff. + sqlite_autoindex_moz_bookmarks_deleted_1: 32KiB (2.2%), 0% eff. + moz_keywords: 32KiB (2.2%), 0% eff. + sqlite_autoindex_moz_keywords_1: 32KiB (2.2%), 0% eff. + sqlite_sequence: 32KiB (2.2%), 0.1% eff. + moz_anno_attributes: 32KiB (2.2%), 0% eff. + sqlite_autoindex_moz_anno_attributes_1: 32KiB (2.2%), 0% eff. + moz_annos: 32KiB (2.2%), 0% eff. + moz_items_annos: 32KiB (2.2%), 0% eff. + moz_meta: 32KiB (2.2%), 0.8% eff. + moz_places_metadata: 32KiB (2.2%), 0% eff. + moz_places_metadata_search_queries: 32KiB (2.2%), 0% eff. + sqlite_autoindex_moz_places_metadata_search_queries_1: 32KiB (2.2%), 0% eff. + moz_places_metadata_snapshots: 32KiB (2.2%), 0% eff. + moz_places_metadata_snapshots_extra: 32KiB (2.2%), 0% eff. + moz_places_metadata_snapshots_groups: 32KiB (2.2%), 0% eff. + moz_places_metadata_groups_to_snapshots: 32KiB (2.2%), 0% eff. + sqlite_stat1: 32KiB (2.2%), 2.4% eff. + moz_places_url_hashindex: 32KiB (2.2%), 3.7% eff. + moz_places_hostindex: 32KiB (2.2%), 7.2% eff. + moz_places_visitcount: 32KiB (2.2%), 2% eff. + moz_places_frecencyindex: 32KiB (2.2%), 2.5% eff. + moz_places_lastvisitdateindex: 32KiB (2.2%), 3% eff. + moz_places_guid_uniqueindex: 32KiB (2.2%), 5.4% eff. + moz_places_originidindex: 32KiB (2.2%), 2.3% eff. + moz_historyvisits_placedateindex: 32KiB (2.2%), 2.5% eff. + moz_historyvisits_fromindex: 32KiB (2.2%), 1.2% eff. + moz_historyvisits_dateindex: 32KiB (2.2%), 2.2% eff. + moz_bookmarks_itemindex: 32KiB (2.2%), 3.1% eff. + moz_bookmarks_parentindex: 32KiB (2.2%), 3.3% eff. + moz_bookmarks_itemlastmodifiedindex: 32KiB (2.2%), 5.8% eff. + moz_bookmarks_dateaddedindex: 32KiB (2.2%), 5.1% eff. + moz_bookmarks_guid_uniqueindex: 32KiB (2.2%), 6.5% eff. + moz_keywords_placepostdata_uniqueindex: 32KiB (2.2%), 0% eff. + moz_annos_placeattributeindex: 32KiB (2.2%), 0% eff. + moz_items_annos_itemattributeindex: 32KiB (2.2%), 0% eff. + moz_places_metadata_placecreated_uniqueindex: 32KiB (2.2%), 0% eff. > Task: _refreshUI

I clicked the "Verify Integrity" button for the Places Database, and here is what I got:

Looks good. The button checks the bookmarks file for errors and tries to repair any found.

As to the changes you made, where/how did you make the changes? And where are the changes not showing up?