hi there, im having the same issue, cant update from 11.15 . im a lifetime member givimg the dropbox error, i dont have dropbox or norton, i have added launchbox and updates folders in allow list on malbytes, and also the update file itself. im losing my mind, why is this such a comon issue, ive spent hours trying to fix it, a fresh install wipes everything, luckily i still had original to put back.