Adam, where do you see this message: on your computer or on your device? How do you connect to Sync on your device: using your Sync account or using the JPack Code (like AAAA - AAAA - AAAA)?

This error I see on my computer. When I try connect with login and sync key, firefox sync says that password is wrong. But when I log on using the firefox browser (https://account.services.mozilla.com) problem with the password does not exist. My android device says: "no password", connect using option: add device. When I created an account on your computer, then I removed them I could not log on again, and data synchronization was not. Thank you for your interest in my problem. Adam

Go to Android Settings > Manage Application and clear Firefox Data. Then try again to connect your device to Desktop Sync. Also make sure that you enter the password correctly on your device. Please let us know if this solution has worked for your issue.

Even know what happened but he just now started to work. I did not do anything other than what I've done lately. Just started working. Previously, I could not log on to usługu Sync, now without a problem. Thank you very much for your help :-)