Error
Error Code:
595
SAP S/4HANA Error 595: Invalid Output Parameter
Description
This error indicates that an API call within SAP S/4HANA attempted to access a parameter as an output parameter, but it was not defined as such. It typically occurs in custom development, integration scenarios, or when calling standard BAPIs/APIs with an incorrect understanding of parameter direction.
Error Message
ERR_API_NOT_OUT_PARAM: Specified parameter is not output parameter
Known Causes
4 known causesIncorrect Parameter Definition
The API or BAPI definition incorrectly marks a parameter as an output when it is designed to be an input-only parameter.
Misuse in Calling Application
The calling program or integration layer attempts to retrieve data from a parameter that the API expects only as an input, not an output.
Inconsistent API Metadata
Discrepancies between the parameter definition in the ABAP Data Dictionary and the actual API signature being called.
Custom Development Error
During custom API or function module development, the parameter direction (e.g., EXPORTING, IMPORTING) was not correctly specified.
Solutions
3 solutions available1. Verify API Call Parameters in ABAP Code medium
Incorrectly defined or passed parameters in ABAP calling an API is the most common cause of this error.
1
Identify the ABAP program or function module that is making the API call. This often involves checking the transaction code or the program that triggered the error message.
2
Examine the ABAP code where the API is being called. Look for the `CALL FUNCTION` or `CALL METHOD` statements.
CALL FUNCTION 'YOUR_API_FUNCTION'
EXPORTING
input_param1 = lv_input_value1
IMPORTING
output_param1 = lv_output_value1 " <--- Check this line
EXCEPTIONS
... .3
Specifically, verify that the parameter listed as an output parameter in the API definition is indeed declared as an `IMPORTING` or `RETURNING` parameter in the ABAP calling program. If it's declared as `EXPORTING` or `TABLES`, it's likely the source of the error.
4
Ensure that the data types of the variables used to receive the output parameter in the calling program match the expected data types of the API's output parameter.
5
If the API is an RFC-enabled function module, check its definition in SE37 to confirm the parameter types. If it's a method of a class, check the class definition in SE24.
2. Review SAP Gateway Service Definition advanced
For OData services, incorrect service implementation in SAP Gateway can lead to this error.
1
Identify the OData service that is being called. This can usually be found in the URL of the request or by checking the application logs.
2
Access the SAP Gateway Service Builder (transaction SEGW) and open the relevant service project.
3
Navigate to the 'Data Model' and then to the relevant Entity Type or Complex Type. Examine the properties defined for these types.
4
Focus on the 'Operations' section (e.g., Create, Read, Update, Delete, Action, Function Import). For custom operations (Actions or Function Imports), verify that the parameters are correctly defined. Ensure any parameters intended to be output are marked as such in the service definition.
5
If the error occurs during the execution of an OData operation, check the corresponding ABAP code in the MPC (Model Provider Class) and DPC (Data Provider Class) for the service. Ensure that the `GET_ENTITY`, `GET_ENTITYSET`, `CREATE_ENTITY`, `UPDATE_ENTITY`, `DELETE_ENTITY`, or the specific action/function import implementation correctly handles and returns output parameters.
6
Look for any custom logic in the DPC extension class that might be manipulating parameters before they are returned to the caller. Incorrectly assigning values to non-output parameters can trigger this error.
3. Check API Interface Definition in SE37/SE24 medium
The fundamental definition of the API itself might be incorrect.
1
Determine the exact name of the function module or method that is causing the error. This can be found in the application logs or by debugging the calling program.
2
Launch transaction SE37 for function modules or SE24 for classes.
3
Enter the name of the function module or class and display its interface.
4
For function modules, examine the 'Importing', 'Exporting', 'Changing', and 'Tables' tabs. Ensure that any parameter intended to return a value is listed under 'Exporting' or 'Tables' (if it's a table parameter).
5
For methods, check the method signature. Parameters marked with `RETURNING` or `EXPORTING` are output parameters. Parameters marked with `IMPORTING` are input parameters.
6
The error 'Specified parameter is not output parameter' usually means that the calling program is trying to assign a value to a parameter that is defined as `IMPORTING` (input-only) or `CHANGING` (bidirectional but not exclusively output) in the API's interface definition.
7
If the API definition is incorrect, it will need to be corrected in the development system and then transported to the target system.