Diagnosis
The IDoc category is not defined for transmission between the sender'sand receiver's logical systems.

System Response
The IDoc cannot be transmitted.

Procedure
Since the IDoc categories are generally predefined, the error can occurbecause of a discrepancy in Customizing. You can maintain the assignmentof IDoc categories which can be transmitted bewteen the SAP System and alogical receiving system with transaction BD64.
Maintain assignment