SAP Message BT064 - The step list editor was called with an invalid operation code (&)

Diagnosis
A call to the function module BP_STEPLIST_EDITOR contains an incorrectvalue for the STEPLIST_OPCODE parameter. The function module call isincorrectly programmed.

System Response
Function terminated.

Procedure
Contact SAP for assistance with this problem, as the function modulebelongs to those that are reserved for internal SAP use only.