In Trados Studio, you are trying to set up a connection to a Trados GroupShare server and you receive the following error message:

The server is not responding. Please check that the server is available.
or
There was a communications or connection error. Please check your server connection settings, network and internet connections, and that the server is available.
or 
Failed to connect to server. Please check your server connection settings, network and internet connections, and that the server is available.
 

1. Go to File > Setup > Servers

2. Double click on the server that you want to connect to and check if the the option The server requires a secure connection (SSL) is selected or not.
    Or Add... the server you want to connect to - fill in the Server Address.

3. Tick the option The server requires a secure connection (SSL) depending on how the Trados GroupShare website connection is set up (HTTP or HTTPS).

For HTTP it does not need to be ticked.
For HTTPS it needs to be ticked, otherwise you will get the connection error.

The Trados GroupShare server requires a specific connection type (HTTP or HTTPS) and that is not set up correctly on the client machine in Trados Studio.

It is also possible that the GroupShare server is not accessible from that machine. To verify that, enter the GroupShare URL in a web browser and see if the page loads. Alternatively try to ping that address and see if there is a response. If neither results in a response, contact local IT.