SOLVED
When importing the tunnel from mullvad, the default device name is "Device: <some name>". When manually adding a configuration, the colon character is invalid, meaning that the imported tunnel from mullvad has an invalid name, and apparently causes the entire unraid UI to die...
The solution is to rename the tunnel.
Solved! (mostly)
I was also unable to access the unraid gui on the host machine, but by changing the boot options (see link) I was able to delete the https certificate, enable ssh, and delete all my existing vpn tunnels. Not sure which one of these resolved the problem but I'm running a check on my array to make sure.
I'm using unraid 6.12.4 and I was modifying my VPN Tunnels, and when after adding a tunnel from from mullvad my unraid UI has stop working. I can access my docker contains not the GUI.
Sorry I am new to this so I am not sure what the problem is, I have attached my diagnostics.
homeserver-diagnostics-20240311-1549.rar