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.