Firefox 29 and later have a new Sync version that use a Firefox account and only use the name and password and no longer use a separate Sync (recovery) key (the Sync key is automatically derived from the password of the Firefox account).

The new Sync version is completely different from the version that was previously used and you need to install a Firefox 29 or later version on all connected devices. You can enter the name and password of the Firefox account on each computer to connect to the new Sync account.

You would need a Firefox 28 version to connect to an old Sync account that used the Sync key.

it dosnt slove my problem

Hi teko2014, it seems that you are using one of the Firefox's latest versions and the new Firefox sync differs from the old one and you may not need the key. So If you want to use the same sync information, you have to Install a older version of Firefox ( Firefox 28 or earlier ).

But I would recommend you to create a new Firefox account and set up a new sync method.

Get more information about the new way of Firefox Sync here: https://support.mozilla.org/en-US/kb/how-do-i-set-up-firefox-sync