Your users get the below error when connecting to SQL Server that has been running fine all along.
What could be the reason? Quite simple. Check to see if the service is running and start it if it is not!
StackOverflow always has the answers for all the other kinds of configuration issues that might cause this error on a new installation but this quick tip is to ensure that you do not overlook the obvious.
TITLE: Connect to Server
Cannot connect to MyBusinessServer.
A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections. (provider: TCP Provider, error: 0 – No connection could be made because the target machine actively refused it.) (Microsoft SQL Server, Error: 10061)