MSSQL: warning: cannot connect to explicitly configured 'MSSQL10.XXXX' server instance: Failed to connect to server XXXX\MSSQL10.XXXX
Steps to resolve
You see the MSSQL10 (or 10_50, etc.) instance when you enumerate the SQL databases in the backup agent on the Microsoft SQL Server.
This is a false error message having to do with the Microsoft SQL Server plug-in searching for a database that doesn’t exist.
In the backup agent on the Microsoft SQL Server, make sure this database is excluded.