Material provision indicator cannot be used

What causes this issue?

In A&D subcontracting you must:
Set the <ZK>Externally processed op. with subcontracting</> indicator in
the operation of a plant maintenance order.
or
Set the subcontracting type to <ZK>Refurbishment</> in the purchase
order item or purchase requisition.
If you are working with an A&D-specific process, you can only use
an A&D-specific material provision indicator (MPI). If you are not
working with an A&D-specific process you cannot use these MPIs.

System Response

The system does not allow further processing.

How to fix this error?

Change the MPI to suit the type of process working with.

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.