Knowledge Base

General log-in problem: Login failed for user '(null)'. Reason: Not associated with a trusted SQL Server connection.

Category: Troubleshooting & error messages
Date: 01 Jul 2011
Product: SQL Backup
You may get the following errors (as shown in the log file)

SQL Backup log file

----------------------------- ERRORS AND WARNINGS -----------------------------

SQL error -2147467259: Communication link failure
SQL error 10054: TCP Provider: An existing connection was forcibly closed by the remote host.

SQL error 18452: Login failed for user '(null)'. Reason: Not associated with a trusted SQL Server connection.

SQL Backup uses the SQL Backup Agent service startup account to connect to the SQL Server instance; here- it is failing.

Check you can connect to the database using (for example) Management Studio.

Check if the password for the SQL Backup Agent service startup account changed recently, or expired.

Finally, try changing the service startup account to another account that has SQL Server sysadmin rights, and try running a backup manually through the SQL Backup GUI.