SAP Message WA451 - Enter a receiver type

Diagnosis
The type linkage links anevent of an object to a particular receiver. The relevant receiver typeis not defined, however.
Alternatively, the receiver type can be determined dynamically atruntime. The receiver type function module required is not defined,however.

Procedure
Enter the receiver type (for example a workflow). Alternatively, youcan specify the receiver type function module, which can be used todetermine the receiver type dynamically at runtime.