We have a class method which is seating behind a task. The class method reads the container for a work item id and then we add an extra field to it, and then we write it back to the work item id container using SAP_WAPI_WRITE_container.
This gives us an error and the error message received is "Cannot call WAPI interface 'SAP_WAPI_WRITE_CONTAINER' in this context".
The return code of FM is 900.
For test purpose i even removed adding the new entry and just tried to write the container that is read, back to the work item id, but still i get the same error.
Has anyone come across this situation before?