When in SAP a data parameter is marked as optional, this does not neccesarily mean that the data field is not required and can be ignored. The data field may be a required parameter for another field when passed into SAP.

Error Scenario

Note: The steps in this article describe one scenario under which this issue may occur. They are simplified and not all steps are shown or described.
When fields of type Flat (String, DateTime, Integer etc…) are marked as IN/OUT (optional or otherwise), the value will not be passed to SAP. Structure and Collection types do not exhibit this problem.

Error Resolution

This Hotfix is contained within the latest K2 connect for SAP Update. Install the update package to resolve the error.

The latest K2 connect for SAP Update is available as an independent installation package which can be found here: K2 connect for SAP downloads