What causes this issue?

You specified in the variant for selecting deliveries that the system
should select only deliveries from the transportation planning point's
company code.
This requirement can only be met if only one company code is valid for
all the different processes carried out to create a transportation
chain. However, the transportation planning points specified in these
processes refer to different company codes.

System Response

In this case, the system issues an error message.

How to fix this error?

Change the transportation planning point by choosing the 'Maintain'
button in the 'Data and options' field of the relevant process. By
doing this, you reach the maintenance screen. Here you can change the
transportation planning point.

Error message extract from SAP system. Copyright SAP SE.