From what you’ve pasted, it looks like it might be trying to grab an incomplete filename for the FW, can you shoot us an email at support@dekunu.tech and we’ll sort you out
For anyone else that experiences this issue, the problem was that the server was down while trying to update the firmware. Usually if you wait 20-30 mins and try again the update should be successful. Failing that, shoot an email to support@dekunu.tech.