Item & is automatically calculated by production order (assembly process)

What causes this issue?

In Customizing, you have stored assembly type "2" for the requirements
class that is assigned to the leading requirements type in the item.
This means that exactly one production order (
<DS:GLOS.3526C7AFAFAB52B9E10000009B38F974>assembly order</>) has been
created for the sales order item.

System Response

The system uses the production order to calculate sales item &v1&
automatically.
The system does not use <DS:GLOS.3526B6D1AFAB52B9E10000009B38F974>sales
order costing</>.

How to fix this error?

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.