There are various symptoms like:

• Term Recognition in Trados Studio or Online Editor is not working anymore when using a server-based Termbase
• Opening server-based Termbases and/or fuzzy searches are not working anymore in MultiTerm Desktop

On the application server where Trados GroupShare is installed, checking the MultiTerm Matrix Cache Service in the Trados GroupShare Console or the Services Console shows that the service is stopped.
Trying to (re-)start the service is resulting in the error/warning:

Windows could not start the [Service Name] service on Local Computer
Error 1053: the service did not respond to the start or control request in a timely fashion.

Workaround: 

1. On the server where Trados GroupShare is installed, go to C:\Users\[USERNAME]\AppData\Roaming\Trados\MultiTerm\MultiTerm17\
2. Open the Settings.xml in a text/xml editor
   Note: Make a backup of the file to avoid any loss in case needed again.
3. Replace the whole content of the file with the following:

   <?xml version="1.0"?><settings />

4. Save the changes.and restart the MultiTerm Matrix Cache Service.

The Settings.xml located by default in C:\Users\[USERNAME]\AppData\Roaming\Trados\MultiTerm\MultiTerm17\ is corrupted.