Well this time in this topic it seems more like a linux file permissions error/mistake.I had a similar problem, made a change to the config file, put the port and opened them in the firewall, and the problem was fixed.
Topic: https://forum.teaspeak.de/index.php?threads/help-plz-ost-file-transfer-connection.2169/#post-15144
U maked a snapshot from Tea*Speak to teaspeak?Yes, thanks