Typo in the login name in the management script. The login was already dropped before the script ran. The script targets the wrong SQL Server instance

Step 1: Verify the login exists: SELECT name FROM sys.server_principals WHERE type IN ('S','U','G') AND name = 'loginname';. Step 2: Check for case sensitivity — SQL Server login names are case-sensitive on case-sensitive collation servers.. Step 3: If the login is missing, create it first: CREATE LOGIN [loginname] WITH PASSWORD = 'StrongPass1!';

Low severityauthentication

Power BI Refresh Error:
15151

What does this error mean?

A management operation (ALTER LOGIN, DROP LOGIN, etc.) references a login that does not exist on the server.

Common causes

1Typo in the login name in the management script
2The login was already dropped before the script ran
3The script targets the wrong SQL Server instance

How to fix it

1Step 1: Verify the login exists: SELECT name FROM sys.server_principals WHERE type IN ('S','U','G') AND name = 'loginname';
2Step 2: Check for case sensitivity — SQL Server login names are case-sensitive on case-sensitive collation servers.
3Step 3: If the login is missing, create it first: CREATE LOGIN [loginname] WITH PASSWORD = 'StrongPass1!';

Frequently asked questions

Is SQL Server login name lookup case-sensitive?

It depends on server collation. On case-sensitive collation, 'MyLogin' and 'mylogin' are different. Always match the case exactly as shown in sys.server_principals.

How do I list all logins on a SQL Server?

Run: SELECT name, type_desc, is_disabled FROM sys.server_principals WHERE type IN ('S','U','G') ORDER BY name;

Can 15151 occur during an ADF linked service test?

No — 15151 is a DDL error raised when managing logins. ADF connection tests trigger login errors like 18456 or 916, not 15151.

Official documentation: https://learn.microsoft.com/en-us/sql/relational-databases/errors-events/database-engine-events-and-errors