Resource Governor Classifier Function Issue [closed]

Question

I’m encountering the following error in the SQL Server error log:

2024-12-03 11:21:01.860 spid568 Error: 10982, Severity: 16, State: 1.
2024-12-03 11:21:01.860 spid568 Failed to run resource governor classifier user-defined function 'dbo.fn_Classifier'. Last error 3602, state 118. See previous errors in SQL Server error log from session ID 568 for details. Classifier elapsed time: 0 ms.

Observations:

1. The classifier function is used in Resource Governor.
2. Error 3602 typically relates to invalid conditions or state in SQL Server.
3. The error suggests that the function failed during classification, preventing proper processing.

My Questions:

1. What are the common causes for a classifier function to fail in Resource Governor?

2. Are there any best practices I should follow to ensure classifier functions execute correctly?

3. What steps can I take to troubleshoot this issue? Are there specific diagnostic tools or approaches to isolate the root cause?

Defenition :

CREATE FUNCTION fn_Classifier
()
RETURNS sysname
WITH SCHEMABINDING
AS
BEGIN
    DECLARE @ReturnValue AS sysname;
    IF (SUSER_NAME() NOT IN (N'##MS_PolicyTsqlExecutionLogin##',N'aaaaa',N'bbbbb',N'bbbbbb',N'ccccc',N'fffff'
                            )
        AND SUSER_NAME() NOT LIKE N'%App%'
       )
        SET @ReturnValue = 'Productionuser_WLG';
    ELSE
        SET @ReturnValue = 'default';
    RETURN @ReturnValue;
END;
GO

Any guidance would be greatly appreciated. Thank you!