KB4486936 - FIX: "Login failed for user" error occurs when you run Maintenance plan with SQL login account in SQL Server 2016 and 2017

Applies to: SQL Server 2016 DeveloperSQL Server 2016 EnterpriseSQL Server 2016 Enterprise Core


Assume that you use a Maintenance plan that runs on a recurring schedule as a SQL Server Agent job to back up a database in Microsoft SQL Server 2016 or 2017. If the credentials of the SQL connection for the job are a SQL user name and a password, the job finishes successfully. However, error entries that resemble the following entry are logged in the SQL Server log:

DateTime Logon       Error: 18456, Severity: 14, State: 8.

DateTime Logon       Login failed for user 'UserName'. Reason: Password did not match that for the login provided. [CLIENT: <LocalMachine>]

Note If the plan is run by Windows authentication, the job finishes successfully without having error entries logged in the SQL Server log.


Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section. 


This issue is fixed in the following cumulative updates for SQL Server:

About cumulative updates for SQL Server:

Each new cumulative update for SQL Server contains all the hotfixes and all the security fixes that were included with the previous cumulative update. Check out the latest cumulative updates for SQL Server:


Learn about the terminology that Microsoft uses to describe software updates.