Unfortunately, I've been away from home this week and haven't been able to test what the support team suggested yet. I will post their response bellow so that you can give it a try. Here it is: Dear Stefan, Do you use our binary on your RPI (downloaded from our site)? If yes, BitTorrent Sync will require password in the following cases: 1) When you launch it for the first time after fresh install, it will offer you to set login/password. If you do not set them and just click "OK", they will not be required anymore. If you do set them- they will be required every time you open webUI. 2) you start it with a config file where credentials are or were configured. Even if credentials are deleted from your config, they are still stored in internal BitTorrent Sync's config and will be asked. To reset password quit BitTorrent Sync, go to .sync folder (hidden folder near binary) or the storage folder (as configured in your config file) and delete settings.dat and settings.dat.old. When you will start BitTorrent Sync next time it will ask you to set a new password. Skip it, if you don't need it. Also, please, note that deleting settings.dat and settings.dat.old will restore all global settings of BitTorrent Sync to defaults: like folders' settings (folders themselves will remain, only their settings will be set to default), BitTorrent Sync settings (like listening port, device name, etc). If you use any other package, please read this package manual. As another means you may completely reinstall BitTorrent Sync. Delete binary and .sync folder from your RPI, download new binary from our site: http://www.bittorrent.com/sync/downloads and do not set the password (unless you actually need it) as suggested in paragraph 1). Thank you. Best regards, *Sync Support Team.