Chef Client 13 will become end-of-life in 2020 end of year. This means that no future feature or security updates will be issued after that date. The Customer want to update to a newer version, that is more secure.

The Customer can uninstall the Chef Client version, and install a newer one, that has no security vulnerabilities. Here are the steps to uninstall/reinstall the Chef Client application:

1. Connect (RDP) to the Trados GroupShare application server with the service user 
2. Download the latest version of Chef Client: https://downloads.chef.io/products/infra-client
3. Open the Trados  GroupShare console -> Services -> Stop services
3. Go to Control Panel -> Programs -> Programs and Features -> Uninstall Chef current version
4. Install the newer Chef Client version 
5. Restart the Trados GroupShare services (https://gateway.sdl.com/apex/communityknowledge?articleName=000003462)

The Chef Client is a third party application, which is used only during the Trados GroupShare / Cumulative Updates installations.
Starting Chef Client 15, the company behind the application, changed the license and we were not commercially compliant with it. So we had to revert to Chef Client 13 which works fine with Trados GroupShare.
We will come up with a solution for this problem, where the newer Trados GroupShare releases will come with a fix for this (like a newer Chef Client application version).