&1: Start date of components in past (T3)

What causes this issue?

The start date of order proposals for the components is in the past.

System Response

This exception message appears in the MRP list for a planning run in
the main memory.

How to fix this error?

Check whether the order proposals for the components are to be
rescheduled and/or converted. You can access these order proposals by
choosing the function 'Order structure' for the receipt you are
viewing.

Error message extract from SAP system. Copyright SAP SE.