I recently applied a firmware update via the web interface to our one of our TeraStation TS5800D. I waited a very long time for the firmware update to finish. It finally came back with a notice that it had finished but couldn't restart the TeraStation. I was able to log back into the box but was not able to make it fully reboot. It said it was rebooting but no power cycle happened. After waiting about an hour, I unpluged it and plugged it back in.
The box came back up but, I cannot log in as admin. Tried admin and password, my old password, and a blank password.
The web interface works.
The Guest account works.