I am having the same issues as @gswave that only started to happen yesterday (Aug 27th). Dropbox is continually restarting no matter what I have tried. There is no error message. The app will disappear from the top menu bar and after a few seconds show up with a 'Starting' status. I have tried going through the settings to see if anything has changed, but even while going through settings the whole app will disappear and restart the cycle.