Such issues can be caused by using Sync to sync bookmarks.

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/kb/Bookmarks+not+saved#w_fix-the-bookmarks-file

If you use Sync then best is to disconnect Sync from all devices while performing maintenance/repair efforts to files in the Firefox profile folder.

Reconnect one device at the time and wait until the initial sync has finished before connecting the next device.

Okay. I have the following related files in my profile folder:

• places.sqlite
• places.sqlite-shm
• places.sqlite-wal

I think I will try the Places Maintenance add-on first.

I ran the Places Maintenance add-on. It found no problems. No action was taken by it.

I still do not see a "corrupted" file in my file explorer.

Also, when Firefox is closed, only the places.sqlite file is listed in my file explorer. The other 2 in my list above disappear.

Sorry I am confused... What should I try next?

Uh-oh... I just went onto my phone and tried to look at the synced webpages from my laptop. I pulled down to sync and now Firefox shows a "Welcome to Sync. Sign in to Sync. Get started." page. Not good...

Here is another interesting anomaly: extra separators at the bottom of my desktop's Bookmarks list. I never added these to my Bookmarks. They also show up in my Bookmarks window. Screenshot of dropdown list is attached.

Just my opinion about the probable cause of both.

Corrupt "Places" due to using Sync with both "Mobile" & "desktop" Firefox. My suspicion is that an improvement made to Sync in spring 2015 during the lead-up to Firefox for iOS going into Beta testing to handle "Mobile Bookmarks" is causing corruption; that corruption is then propagated via Sync to all connected devices.

To fix bookmarks data corruption that is "stuck" in Sync do this: Follow all the steps or the corruption will not be rectified; more threads around here with failure to effect a fix that there are reports of success. 1. Disable Sync on all devices until all devices are fixed. 2. Run Places Maintenance on all devices, to effect a fix of the Places database on each device, https://addons.mozilla.org/en-US/firefox/addon/places-maintenance/ 3. Change your Firefox Account password (for Sync) to clear the corrupt data from the Sync server. 4. Then connect the first "desktop" device to the Sync server and let that device to stay connected to Sync for an extended period (IOW, keep Firefox on that device running for a long time). 5. The following day connect the 2nd "desktop" device to Sync and let that one run for an extended period. Make sure that your bookmarks are synchronizing correctly and you aren't losing any of them or seeing them getting corrupted in any manner. 6. Don't connect the "mobile" device to Sync for a few days (if at all). And if that is a "game changer" for you with using Sync, see if this corruption issue has been fixed unbeknownst to me by giving it a try.

Please keep us posted as to how that works out for you.

Note: Firefox 49.0 got a new feature for "Places Database - Verify Integrity" on the internal about:support page - accessed via Help > Troubleshooting Information in Firefox or typed in the URL bar. Scroll down that page almost all the way to below "Important Locked Preferences" to access that new feature. I'm not sure if that feature fully replaces the need for using the Places Maintenance extension or not. Seems to work for me, and the "report" does seem to cover what the extension does. Might be worth trying ...

Can you remove these separators in the Bookmarks Manager (Library)?

You can try to restore an older compressed .jsonlz4 in the Bookmarks Manager (Library).

• Bookmarks -> Show All Bookmarks -> Import & Backup > Restore

Maybe a difference in item count makes it possible to find a not corrupted backup.

The name of a JSON bookmarks backup file includes a total item count (folders and separators included) and an hash value to prevent saving the same backup more than once.

• bookmarks-YYYY-MM-DD_<item count>_<hash>.jsonlz4.

@the-edmeister I will try the directions you posted and report my findings...

@cor-el Yes, I can delete the separators. When I delete them, they are also deleted from the other instances of Bookmarks Menu. ...which leads me to believe that this is probably not a corrupted Library on my PC, but rather a problem with Sync or some other Firefox function.

Wow, I just noticed that my Android phone has 2 identical-looking accounts in "about:logins":

https://accounts.firefox.com [my email address, same for both entries]

I deleted one of them. Will try restarting and see if any duplicate entries in Library disappear, before doing suggestion from @the-edmeister.

Note that the places.sqlite-shm and places.sqlite-wal are temporary SQLite files.

wal: Write-Ahead Logging
shm: Shared Memory files

I disconnected all 3 devices from Sync. The problem seems to be only on my Lenovo laptop. The other devices do not show multiple instances of any Library info.

>> Regarding cor-el's ideas...

There has been no jump in file size or number of items in any of the saved Bookmarks backups, dating all the way back to 2016-09-14 (my HP laptop). I just installed Firefox onto my Lenovo on 2016-12-16.

In total, I am getting 3 instances of each Library category. 1 looks to be the desired one, plus 2 duplicates. ...but I do not have 3 sets of data stored on my PC. Instead, the data appears to be recalled 3 times.

Is it possible that the program which is supposed to recall my Library is doing multiple calls regarding Library items, and then displaying the results of each call, instead of merely 1?

>> Regarding the-edmeister's ideas...

Places Maintenance found nothing on either computer (I have 2 laptops) and is not available on my Android phone.

"Verify Integrity" under Places Database found nothing. I see it on my Android phone, but it does nothing when I tap the link.

Here is the Places Maintenance output from my Lenovo:

> Integrity check + The database is sane > Coherence check + The database is coherent > Orphans expiration + Database cleaned up > Vacuum Initial database size is 10240 KiB + The database has been vacuumed Final database size is 10240 KiB > Statistics Database size is 10240 KiB user_version is 33 page_size is 32768 cache_size is -2048 journal_mode is wal synchronous is 1 History can store a maximum of 65949 unique pages Table moz_places has 3814 records Table moz_historyvisits has 42 records Table moz_inputhistory has 0 records Table moz_hosts has 1669 records Table moz_bookmarks has 4703 records Table moz_keywords has 1 records Table sqlite_sequence has 1 records Table moz_favicons has 85 records Table moz_anno_attributes has 8 records Table moz_annos has 45 records Table moz_items_annos has 2257 records Table sqlite_stat1 has 14 records Index sqlite_autoindex_moz_inputhistory_1 Index sqlite_autoindex_moz_hosts_1 Index sqlite_autoindex_moz_keywords_1 Index sqlite_autoindex_moz_favicons_1 Index sqlite_autoindex_moz_anno_attributes_1 Index moz_places_url_hashindex Index moz_places_faviconindex Index moz_places_hostindex Index moz_places_visitcount Index moz_places_frecencyindex Index moz_places_lastvisitdateindex Index moz_historyvisits_placedateindex Index moz_historyvisits_fromindex Index moz_historyvisits_dateindex Index moz_bookmarks_itemindex Index moz_bookmarks_parentindex Index moz_bookmarks_itemlastmodifiedindex Index moz_places_guid_uniqueindex Index moz_bookmarks_guid_uniqueindex Index moz_keywords_placepostdata_uniqueindex Index moz_annos_placeattributeindex Index moz_items_annos_itemattributeindex

Starting to wonder if I should just reinstall Firefox on my Lenovo laptop. Thoughts?

Devices:

• Lenovo laptop, Win7Pro (has the FF Library problems)
• HP laptop, WinXP
• Samsung phone, Android 5.1.1

@cor-el said: Maybe a difference in item count makes it possible to find a not corrupted backup.

Me: No. I looked through the HTML version and see no repeats. Every backup has at least a slightly different item count because I use Bookmarks all the time. No two backups are the same. I think I have more than 1000 Bookmarks.

Question #1: What exactly is corrupted?

Does not seem to be the Bookmarks json file itself, but something that reads and posts from it.

Question #2: If I delete "places.sqlite" while Firefox is closed, will it regenerate itself?

When you delete all places.sqlite files including places.sqlite-shm and places.sqlite-wal then Firefox will recreate places.sqlite file and use either a bookmarks.html file in the main profile folder or the most recent backup in the bookmarkbackups folder. Restoring a JSON backup shouldn't cause problems, but importing an HTML backup can sometimes cause issues with merging the bookmarks and place them in the correct bookmarks system folder (Bookmarks Menu, Bookmarks Toolbar, Other Bookmarks).

YES! I think the problem is fixed. No more excessive instances of Library contents. Here is what I did:

1. Create a backup file of Bookmarks, just in case...
2. Close Firefox fully via menu (3 horizontal bars in top right corner, click the power on/off icon).
3. Delete the file "places.sqlite" from AppData folder for Firefox. On Win7Pro OS, my location was: C:\Users\[myUsername]\AppData\Roaming\Mozilla\Firefox\Profiles\[randomLetters].default
4. Open Firefox.
5. Check the Library for multiple instances. Can open via <ctrl><shift><letter B> or Open All Bookmarks, etc.

I had done some more research and found (via other forum questions) that places.sqlite can become corrupted, but also that places.sqlite can regenerate itself if you delete it. Upon regeneration, it tends to be a good working file. ...so I tried this and it worked!

The file size of the regenerated places.sqlite is very close to previously.

Also, I would like to point out that all former Bookmarks are still intact (thankfully!), but History was deleted For anyone using Tags: I had not ever used any Tags, so I do not know whether those would have been deleted.

I just wish I had tried this before disconnecting anything from Sync :( Now I have to deal with reconnecting 3 devices to Sync without getting duplicate Bookmarks. (My problem for this thread was not duplicates! It was multiple instances of displaying a single set of Bookmarks.)

continuation of this problem - i.e., reconnecting the other devices to Sync is in this thread - /questions/1152982