Settlement of incoming order data only allowed with receiver cat. PSG

What causes this issue?

You can only settle incoming order data to a profitability segment.
During settlement of the incoming order data, the system considers the
manually created distribution rules for incoming orders. If no
distribution rules have been maintained for the incoming orders, the
system copies the actual rule to the profitability segment.
You have either:
Created a distribution rule for the incoming orders with a receiver
that is not a profitability segment or
No distribution rule exists for the incoming orders
And there is no actual rule for the receiver "Profitability segment".

How to fix this error?

Maintain the settlement rules for the sender. Create a distribution
rule with receiver "Profitability segment" for settlement of the
incoming orders.

Error message extract from SAP system. Copyright SAP SE.