The services could not connect to the database.

Possible reasons for the message:

The database server may not be allowing remote connections, make sure the database server is setup correctly and that the firewall in not blocking the connections.

The KB here did not help me : https://support.citrix.com/article/CTX233581

Solution:

Set the service : SQL Server Browser to Automatic and Start

Make sure TCP/IP is enabled and a TCP port is set ( If this is not the database service will need to be restarted )