Error occurred in creating schedule line for supplier &1

What causes this issue?

A schedule line generation error occurred in determining purchase orders
and sales orders for collective purchase order processing.

System Response

INCLUDE ISR_STOP

How to fix this error?

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

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.