I have a big problem. I lost my other device, and Sync doesn't recognize my Recover Key, even if I generate a new one. What to do? I have all my bookmarks there

If you have generated a new Recovery Key, then unfortunately the account data that you had before is gone (Sync will wipe all data before creating a new key to ensure it stays secure). So unfortunately at this point, unless you have a backup of your data somewhere, it is inacessible.

I've lost my Firefox Sync account information - What to do

Can you login to that sync account?

• https://services.mozilla.com/ Firefox Sync » Home
• https://account.services.mozilla.com/

• https://support.mozilla.org/kb/ive-lost-my-firefox-sync-account-information
• https://support.mozilla.org/kb/how-do-i-manage-my-firefox-sync-account