issedpoff said

did the transfer from the external hard drive

Did you copy the whole folder? Did you get your setting, passwords, history . . . . Are the bookmarks empty? What is inside?

The places.sqlite file contains your History and Bookmarks.

thanks for the reply

when i say i did the transfer, it was just the standard apple time machine back up method where you connect the external mybook hard drive to your new iMac... exactly what it transfers i don't know.

I'm not very tech minded as far as files and coding goes. where is the places.sqlite file found?

i used this method to back up on the 2009 imac https://support.mozilla.org/en-US/kb/restore-bookmarks-from-backup-or-move-them

at the moment on the new imac i closed down firefox and reopened it and then it wouldn't open so then i tried to download and install quantum but the same thing happened 'your firefox profile cannot be loaded. it may be missing or inaccessible'.

i can still use it on the old imac though?

Don't know if originally i got setting, passwords, history . . . . but bookmarks were empty

I don't know Macs and called for more help.

thank you Fred

Did you look at this article?

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

Did you copy profiles.ini as well?

Note that you can use the JSON backups in the bookmarkbackups folder to restore the bookmarks or transfer places.sqlite.

You can copy files like these with Firefox closed to the current profile folder to recover specific data.

• 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)

See also:

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

firefox has returned to normal.... I turned the new iMac off and on again.

Thank you for the help though I really appreciate it, I didn't want to have start using goggle chrome!