Orders of the order type & cannot be confirmed

What causes this issue?

You want to confirm a network/order of the order type &V1&. However,
this order type is allocated to an order category whose confirmation
is not intended in this transaction.

How can this happen?

You try to confirm a network using a transaction intended for
confirming production orders. Since networks and production orders are
assigned to different order categories, the system issues an error
message.

How to fix this error?

Enter an order of an order type that is intended for this transaction.

Error message extract from SAP system. Copyright SAP SE.