After the yesterday update patch for MMO-Bugs MQ2 there was no "out of sync" anymore. Once I had a task disappearing without any error message (which happened this year always from time to time when porting or esp. when changing picks with a lot of toons.
That "Server out of sync" is a very strange thing. This happened only on one of the accounts which I played around for testing purposes but now its gone for the last evening.