Hi, always for the future :

• https://support.mozilla.org/en-US/kb/back-and-restore-information-firefox-profiles
• https://support.mozilla.org/en-US/kb/export-firefox-bookmarks-to-backup-or-transfer

Find your New Profile with Firefox closed :

• https://support.mozilla.org/en-US/kb/profiles-where-firefox-stores-user-data

You can copy files like these with Firefox closed to the current profile folder to recover specific data. Never work with original files, always copies. Do not transfer back that problem that existed to begin with.

• https://support.mozilla.org/en-US/kb/recover-lost-or-missing-bookmarks
• http://kb.mozillazine.org/Transferring_data_to_a_new_profile_-_Firefox
• https://support.mozilla.org/en-US/kb/recovering-important-data-from-an-old-profile

What's What in the Profile :

• bookmarks and history: places.sqlite
• bookmark backups: compressed .jsonlz4 JSON backups in the bookmarkbackups folder
• cookies.sqlite for the Cookies
• formhistory.sqlite for saved autocomplete Form Data
• logins.json (passwords) and key4.db (58+) or key3.db (57 and older) (decryption key) for Passwords saved in the Password Manager
• if you only have key3.db then make sure to remove an existing key4.db
• cert9.db (58+) or cert8.db (57 and older) for (intermediate) certificates stored in the Certificate Manager
• if you only have cert8.db then make sure to remove an existing cert9.db
• persdict.dat for words you added to the spelling checker dictionary
• permissions.sqlite for Permissions and possibly content-prefs.sqlite for other website specific data (Site Preferences)
• sessionstore.jsonlz4 for open tabs and pinned tabs (see also the sessionstore-backups folder)

Look on your desktop. Do you see a folder called; Old Firefox?

https://support.mozilla.org/en-US/kb/recovering-important-data-from-an-old-profile

https://support.mozilla.org/en-US/kb/back-and-restore-information-firefox-profiles

https://support.mozilla.org/en-US/kb/how-run-firefox-when-profile-missing-inaccessible

If bookmarks and/or session is corrupted : If a jsonlz4 backup can't be imported restored because it has the same structural problem as the database, a user can try to fix it using the Check/Repair JSON button on this page: https://www.jeffersonscher.com/res/scrounger_json.html Bookmarks : https://www.jeffersonscher.com/res/bookbackreader.html

Please let us know if this solved your issue or if need further assistance.

I am not as savvy as I thought I was. Can someone walk me through this process?

Thank you.

When you are ready, we can start moving parts of your old data and Copy it to the new profile.

First; open your file browser to the New profile;

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.

Linux: Under the page logo on the left side, you will see Application Basics. Under this find Profile Directory. To its right press the button Open Directory.

Second, open another file browser to the Old profile.

Open another file browser to the Old Firefox folder on your desktop. Then open the folder with the latest date.

Warning ! ! Only Copy the files you are told. We will avoid anything that might cause problems. Here is the list of files;

cookies: cookies.sqlite Do not bother. Cookies will be created when you return to the website. However, you will have to log in everywhere. And you may lose any settings that websites store on your computer.

extensions(add-ons, themes): it would be better to download them fresh. ++++++++++++++++++++++++++++++++ key3.db [v58+] key4.db and logins.json : These are the password files. Copy Both !

persdict.dat : custom dictionary – words you added to the dictionary

mimeTypes.rdf : What to do with what type of file. handlers.json : In Firefox v55+ the name was changed.

places.sqlite : History and Bookmarks.

prefs.js : Your settings. Note: If you were having problems, this could be contaminated.

cert8.db [v58+]cert9.db and possibly cert_override.txt : Stores all your security certificate settings and any SSL certificates you have imported into Firefox. If removed, the cert8.db, cert9.db file will be replaced.

search.json.mozlz4 : file stores the user-installed search engines that are available in the Firefox v47+

search.sqlite file and searchplugins folder store the search engines that are available in the Firefox Search bar before Firefox v47 +++++++++++++++++++++++++++++++++++++++++++++++++ Copy these files from the old to the new. You may get a message that the files already exist. Choose to over-write for each file.

Did you locate the "Old Firefox Data" folder on the desktop?

when you use the refresh feature in Firefox then a new profile is created and some personal data (bookmarks and history, form data, tabs) is automatically imported. The current profile folder will be moved to an "Old Firefox Data" folder on the desktop. Installed extensions and other customizations (toolbars, prefs) that you have made are lost and need to be redone.

It is possible to recover data from the "Old Firefox Data" folder on the desktop, but be cautious not to copy corrupted files to avoid carrying over problems.

Firefox being slow can be caused by issues with places.sqlite, so maybe best would be to restore the bookmarks from a JSON backup from the bookmarkbackups folder in the "Old Firefox Data" folder on the desktop.

• Bookmarks -> Show All Bookmarks -> Import & Backup -> Restore
• https://support.mozilla.org/en-US/kb/restore-bookmarks-from-backup-or-move-them
• https://support.mozilla.org/en-US/kb/recovering-important-data-from-an-old-profile