Firefox Sync is just not designed to back up your information.

It it is not even very good at syncing bookmarks, and personally (I know developers say similar). If you Sync bookmarks you also need to manually back them up because there is a danger Sync will corrupt them.

Do you have Firefox data on other devices or other |devices|backups ?

We may be able to offer suggestions on recovering from a previous computer, its hdd, or some |backup|disk image| you may still have.

no. I can not get my old computer. so i can not backup manually. I guess, this data be Backing Up in the FireFox. If I send mail, Do they send backups ?

Have you still got the old computer, its hard disk drive, or any backups from that old computer ?

You can open the about:sync-log page via the location/address bar if there are error logs available. If there are then please attach a recent log. You can upload a recent log to this website if the log is too big to put in a reply.

• http://pastebin.mozilla.org

no, I don't have my old computer. when open about:sync-log page, this page empty. so no error. firefox installed on this computer new.

Did you have any problem logging into Firefox Accounts / Sync on the new PC? Like maybe you had to request a new account Password?

I forgot my password. I reset my password. then I logged on to my new computer with a new password. but I did not receive any errors. I logged in successfully.

You have a new computer. Have you got some other device to Sync with ? Otherwise there is no point in using Firefox Sync.

I am sorry to say but unless you backed-up or kept Firefox data from the old computer, but it appears you did not. Then it is lost.

I had my old computer to sync session. then i logged on to my new computer sync. now my data on old computer did not come to the new Firefox. Does this data is not backed up in Firefox? When I logged, It does not need to be added to the Firefox?

Firefox keeps data locally in a set of files and folders refererd to as the profile.

• Profiles - Where Firefox stores your bookmarks, passwords and other user data

Firefox sync tries to temporarily store some of that data and allows it to be transfered or Synced to another device. The other device may then be considered to be a backup.

You need to be aware that Sync does not alway work successfully, and is particularly prone to fail and corrupt bookmarks. If you elect to Sync bookmarks you should always also regularly manually back up your bookmarks locally.

• Restore bookmarks from backup or move them to another computer

stronger said

I forgot my password. I reset my password. then I logged on to my new computer with a new password. but I did not receive any errors. I logged in successfully.

Unfortunately Reseting the password clears all the data.

Also see

• I've lost my Firefox Sync account information - What to do
• Firefox Sync troubleshooting and tips

My profile is not registered in Firefox Sync? not local, i ask in firefox servers ? I do not have opportunity to reach my old computer. and I'm looking for the way to get back to my profile. sync is not working. If I send mail, Do firefox managers send backups with mail? Is it possible?

Sorry, requesting a new Password was a "fatal" mistake.

The old Password that you reset was used as a part of the encryption key for your data while your data is away from your devices; both "in-transit" and while on the Sync server. Without that exact "key" your data is/was useless, thus deleted from the server when you requested a new password. There is nothing that Mozilla can do to recover your data to email it to you; the system isn't set up for it, and even if it was your data would be unreadable without that "key" which isn't "user facing".

so, all data was lost?

Yes it's gone from the Sync server due to requesting a new Password for your Sync account.

it is bad news for me. thanks for answers.

The currently used new Sync version still uses the Sync key to encrypt data locally before uploading, but this Sync key is generated internally from the password of your Firefox account, so you no longer need to worry about it. This means that the Sync key changes when you change the password of the Firefox account and you lose all data stored on the Sync server doing that.