short dump: "Data objects in a Unicode program are not convertibe"

[Korman, Peter]

Hello workflowers,
 
I've following problem:
 
I get a shortdump while testing a method with a function module in my =
subtype ZBUS2081 (incoming invoice).
 
The funcion module reads the purchasing group out of table MARC using a =
select with EBELN and EBELP.
EBELN and EBELP are determined by reading the invoice positions.
 
The method has an export- parameter with a data type reference on object =
type T024 (purchasing group).
I suppose this is the problem.
 
I didn't get any shortdumps, when I changed the data type reference to =
ABAP Dictionary reference table T024 and reference field EKGRP.
This worked pretty fine. But I need the purchasing group within the =
object type, otherwise the agent could not be found using rule 00900010.
Rule 00900010 requires at binding using a parameter with an object type =
T024.
 
Where's the bug? How could I get the purchasing group determined and =
filled in the object type T024?
 
B.t.w the method is started in a task used in a dynamic parallel =
workflow for LIV-process.=20
The number of subworkflows depends on the quantity of blocked invoice =
positions. My task should find the right user by running the rule with =
the purchasing group.
 
 
Your help is highly apreciated!
 
Regards,
Peter Korman