OutBound datasource is null

Error:

We are setting up a new customer and have completed the outbound setup under B2B. We continue to get the following error when we trigger the file.

Error in execution for activity CustomPlugin:CP_ToReadFileSource:1921680011591245
82736828100002[OutBound datasource is null for event id = FileEvent:

Cause:

The event registry entry created for this relationship was created manually instead of automatically created by the B2B trading partner

Solution:

Remove the existing event registry associated to this relationship. Recreate the relationship and allow the event registry entry to be automatically created