Schedule vehicle &1 (departure time &2) is not required

What causes this issue?

Schedule vehicle &V1& (departure time: &V2& seconds after the start of
the planning horizon) cannot be used for optimization. This might be due
to the following:
The schedule vehicle is incompatible with the orders or their
transportation groups.
Orders cannot be scheduled on the schedule vehicle at feasible times.
The schedule vehicle's capacity is insufficient for transporting the
orders.
In most circumstances, a combination of the above reasons leads to the
schedule vehicle being excluded.

System Response

The system will no longer take the schedule vehicle into account for
optimization.

How to fix this error?

You do not need to select this schedule vehicle in the subsequent
optimization runs for these orders. It is only a good idea to select it
again if you have selected other orders or have changed the master data
for this schedule vehicle.

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.