How To Fix OO331 - Method &1 &2: Invalid method type for alias method (ALIAS/MTDTYPE)

SAP Error Message - Details

• Message type: E = Error

• Message class: OO - Class Builder/API

• Message number: 331

• Message text: Method &1 &2: Invalid method type for alias method (ALIAS/MTDTYPE)

Self-Explanatory Message

Since SAP believes that this specific error message is 'self-explanatory,' no more information has been given.The majority of messages in the SAP system have a message text, however this is frequently insufficient to comprehend or resolve the problem.

To make things easier, more detailed information is frequently added to describe the issue, how to fix it, and the necessary steps or configuration modifications.

Unfortunately, there isn't any extra information in this error notice.

What else can you do?

First, use our AnswerBot below to get a possible cause and solution (requires a premium subscription).

Also, review the in-depth Common Questions & Answers listed below; you could discover a solution there or be able to connect with others who have faced similar challenges.

You can also try searching the SAP support portal (support.sap.com) but you need a special user ID to access it. It is possible that an SAP support note exists that provides additional details about the mistake or even steps for fixing it.

Smart SAP Assistant

• What is the cause and solution for SAP error message OO331 - Method &1 &2: Invalid method type for alias method (ALIAS/MTDTYPE) ?

  The SAP error message OO331 indicates that there is an issue with the method type for an alias method in the context of Object-Oriented Programming (OOP) in ABAP. This error typically arises when the method type defined for an alias method does not match the expected type.
  Cause:
  The error can occur due to several reasons:
  
  Incorrect Method Type: The method type defined for the alias method does not correspond to the expected type (e.g., it might be defined as a non-virtual method when it should be virtual).
  Alias Method Definition: The alias method may not be correctly defined in the class or interface.
  Inheritance Issues: If the alias method is supposed to inherit from a parent class or interface, there may be a mismatch in the method definitions.
  Typographical Errors: There could be typographical errors in the method name or parameters.
  
  Solution:
  To resolve the OO331 error, you can follow these steps:
  
  
  Check Method Definition: Verify the method definition for the alias method. Ensure that the method type (e.g., PUBLIC, PROTECTED, PRIVATE, VIRTUAL, FINAL, etc.) is correctly defined.
  
  
  Review Alias Method: Ensure that the alias method is correctly defined and that it points to a valid method in the class or interface.
  
  
  Check Inheritance: If the alias method is supposed to inherit from a parent class or interface, check that the parent class/interface has the method defined with the correct type.
  
  
  Correct Typographical Errors: Look for any typographical errors in the method name or parameters that could lead to this error.
  
  
  Recompile the Class: After making changes, recompile the class or interface to ensure that the changes take effect.
  
  
  Consult Documentation: If you are unsure about the method types and their definitions, refer to the SAP documentation or ABAP programming guidelines for clarification.
  
  
  Related Information:
  
  ABAP Object-Oriented Programming: Understanding the principles of OOP in ABAP can help in diagnosing and fixing such errors.
  SAP Notes: Check SAP Notes for any known issues or patches related to this error message.
  Debugging Tools: Utilize debugging tools in the ABAP Workbench to trace the execution and identify where the error occurs.
  
  By following these steps, you should be able to identify and resolve the cause of the OO331 error in your SAP environment.