Subcontracting PurchReq from location &1 to loation &2 not created

What causes this issue?

The following causes are possible:
No handling resource has been specified in one of the locations
involved.
No transportation resource has been specified in the transportation
lane between the locations.
These resources must be available for subcontracting since the system
executes detailed scheduling for the relevant orders on the basis of
the resource calendar. (The relevant orders are a purchase requisition
in your own location and a planned order at the subcontractor's
location. The orders are linked by a cross-order relationship.)

System Response

The system cannot create the subcontracting purchase requisition.

How to fix this error?

Enter the resources required in the location or in the transportation
lane.

Procedure for System Administrators

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

Error message extract from SAP system. Copyright SAP SE.