I had firefox sync on my laptop and desktop, and it worked fine. On getting a new desktop, I tried to sign in to sync, but I get an "Unknown account" error when ever I do. But I have my laptop next to me, signed in to sync, on that account. Is this some problem with the new version of sync not recognizing old version accounts? It says in order to update to new sync, I have to unlink all my accounts. But I don't want to do that if I can't sign in to recover my sync. I'm not sure what to do here.