hello, when you type about:sync-log into the address bar and open the latest one or two error logs, can you copy their contents and put them into http://pastebin.mozilla.org/ or a similar service and paste a link here on the forum? this would be very helpful in assessing the problem. thank you!

please have a look here

http://pastebin.mozilla.org/7586967

does it make a difference if you log out of the account & sign in again? the error seems to be with syncing your history, so you also might want to try to exempt that item from being synced...

Massive number of DATA LOSS lines in that log. Looks like a real FUBAR.

Open Sync preferences on each device and Unlink from Sync on every device at the same time, so none are connected to the Firefox Accounts server.

Then reconnect each device one-at-a-time at {say} one hour intervals and see what happens. Make sure that about:sync-progress shows Setup Complete in each device before proceeding to the next device.

Or, Unlink them all and create a new Firefox Account and start from scratch.

I have created a new account and I got that issue...I have desync all my devices and I got the issue twith that log file... What next?

TNX