18456

Product Name

Event ID

18456

Event Source

MSSQLSERVER

Component

SQLEngine

Symbolic Name

LOGON_FAILED

Message Text

Login failed for user ’%.*ls’.%.*ls

You get this error message when a connection attempt is rejected because of an authentication

failure. User logins can fail for many reasons, such as invalid credentials, password expiration,

and enabling the wrong authentication mode. In many cases, error codes include descriptions.

The following examples are some of the common login failures. Select the exact error that

you’re experiencing to troubleshoot the issue:

Login failed for user '' or login failed for user ‘<username>’

Login failed for user ‘NT AUTHORITY\ANONYMOUS’ LOGON

Login failed for user ‘empty’

Login failed for user ‘(null)’

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