Order &1: Error scheduling the start/end date

What causes this issue?

An error occurred when scheduling order &V1&.
Possible reasons for the error:
The (production) location of the order is not assigned to any calendar.
An error occurred reading the material master data.

System Response

The order was not scheduled.

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.