How To Fix FL399 - With RFC, no generic types (secondary properties) allowed

SAP Error Message - Details

• Message type: E = Error

• Message class: FL - Function Builder messages

• Message number: 399

• Message text: With RFC, no generic types (secondary properties) allowed

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 FL399 - With RFC, no generic types (secondary properties) allowed ?

  The SAP error message FL399 ("With RFC, no generic types (secondary properties) allowed") typically occurs when there is an attempt to use a generic type or a secondary property in a Remote Function Call (RFC) context. This is a common issue when working with RFC-enabled function modules in SAP, especially when dealing with complex data types or structures that include generic types.
  Cause:
  
  Generic Types: The error arises because RFC does not support generic types. This means that if you are trying to pass a structure or table that contains fields defined with generic types (like ANY, STRING, or other non-specific types), the RFC call will fail.
  Secondary Properties: Secondary properties refer to additional attributes or metadata associated with a data type that are not directly part of the data structure. These are not supported in RFC calls.
  
  Solution:
  To resolve this error, you can take the following steps:
  
  
  Check Data Types: Review the data types being passed in the RFC call. Ensure that all structures and tables use specific, concrete types rather than generic types. Replace any generic types with specific types that are compatible with RFC.
  
  
  Modify Function Module: If you have control over the function module being called, consider modifying it to avoid using generic types or secondary properties. Ensure that the parameters are defined with specific types.
  
  
  Use Compatible Structures: If you are using structures that are defined in the ABAP Dictionary, ensure that they are compatible with RFC. You may need to create a new structure that mirrors the original but uses specific types.
  
  
  Testing: After making changes, test the RFC call again to ensure that the error is resolved.
  
  
  Related Information:
  
  RFC (Remote Function Call): A protocol used in SAP to enable communication between different SAP systems or between SAP and non-SAP systems.
  Data Types in ABAP: Understanding the different data types in ABAP is crucial. Avoid using types like ANY or STRING in RFC-enabled function modules.
  SAP Notes: Check SAP Notes for any specific patches or updates related to this error message. Sometimes, SAP provides fixes or workarounds for known issues.
  
  Additional Tips:
  
  If you are using third-party tools or libraries to generate RFC calls, ensure that they are configured correctly to handle data types.
  Consult the SAP documentation for best practices on defining RFC-enabled function modules and the data types that can be used.
  
  By following these guidelines, you should be able to resolve the FL399 error and successfully execute your RFC calls.