If you are unable to stay connected, change channels or receive the message "the remote host closed the connection", this is usually caused by some firewalls interacting with mumble's network packets.
Try disabling the Quality of Service optimizations in your mumble client:
Be sure to follow these instructions EXACTLY, especially Step 2
Windows:
- Click "Configure" => "Settings"
- Look down to the bottom left corner and activate the "Advanced" checkbox
- Click on "Network" on the left side panel
- Under "Connection", deactivate/uncheck "Use Quality of Service"
- Try reconnecting to your server
Be sure to follow these instructions EXACTLY, especially Step 2
Windows:
- Click "Configure" => "Settings"
- Look down to the bottom left corner and activate the "Advanced" checkbox
- Click on "Network" on the left side panel
- Under "Connection", activate/check "Force TCP Mode"
- Try reconnecting to your server