if TeamViewer is unresponsive, but myServer is operational:
From a browser on the network connect to http://myserveripaddress/dashboard
then run:
run|sudo~teamviewer daemon restart
On later 6.8 systems, you can use myServer's linux terminal under the Utilities Menu. User name allonis / password allonis
You can try to update the OS and reboot:
From Dashboard open a command prompt and enter:
run|sudo~apt update && sudo apt upgrade -y && sudo reboot
It may also be possible to connect to the myServer controller and copy files off.
From a LAN connected PC, go to File Manager: \\192.168.1.x\myServer
You can grab the database in the data directory and the HTML folder from wwwroot folder.