INFO [GameController.setModel] ++++++++ New Model: CONNECT #0 +++++++++++++++++++++++++++++++++++++++++++
INFO [Server.<init>] Server: Creating
INFO [Server.<init>] Server: Started on TCP address /0.0.0.0:6260
INFO [Server.<init>] Server: Started on UDP address /0.0.0.0:6260
INFO [Client.connect] Client connects...
INFO [Client.connect] Client UDP local address: 0.0.0.0/0.0.0.0:6261
INFO [Client.connect] Client: Connects TCP: /127.0.0.1:6260 UDP: /127.0.0.1:6260
WARNING [ConnectPhase.begin] Client failed to connect to server: SOCKET EXCEPTION: Operation not supported
Looks like you successfully started a local server and the client then tried to connect to it but failed while setting up the connection socket with "Operation not supported". Have you checked whether this can be related to AppArmor?