i have windows7 x64, the latest firefox, initially it worked, but after some time started the error messages, and after latest firefox update, stopped to sync. my addons
It does not what to sync you add-ons from where to where? Are you sure the sync key is correct? Have you looked at the help article Firefox Sync troubleshooting and tips ?
sync with server, when i look in options, addons sync is disable, i enable it, and after some time in quota, addons size is 0, and so on..
Not many of us here specialize with sync. Your best bet is to file a bug with bugzilla here: https://bugzilla.mozilla.org/