Hi

Thank you for your question about the Firefox Sync service.

It appears from your question, that you are using Firefox Sync as a back up service. This is not what Sync is designed to do. The Firefox Sync service takes a copy of the data you wish to include and transfers it to a second device (typically a mobile device such as a tablet or a telephone) running a copy of Firefox. The storage in between all attached devices is both temporary and fragile and is not stable enough to be (and is not designed as) a reliable backup service.

If you have a copy of your Firefox profile for desktop Firefox, you may be able to recover your bookmarks and other data. Please have a read of this article.

If you have a copy of your data on a mobile version of Firefox, please follow these instructions to connect it to Firefox Sync to copy your data.

Thank you. I mean, when I install new firefox, firefox shows up on the sync frame, instead of clicking "already have an account" and then filling in the account to log in, but unaware, I filled in the " Sign account ". But firefox does not show that the email is registered, firefox is registered as a new account. As a result, when you log in, all your previous bookmarks are gone. Firefox identifies the email as a completely new account. Old firefox on my old hdd has been reformatted, so I just asked for support from firefox.