No parameter variant in the referenced sales order item

What causes this issue?

You create a production order with reference to a sales order item and
for a material for which a parameter variant is planned. However, no
parameter variant that could be used when the production order is
exploded is entered in the sales order item. Therefore, the production
order is exploded without a parameter variant. This has the following
consequences:
All change numbers with parameter effectivity are invalid for the
explosion. Therefore, the changes in question are not incorporated into
the production order.
You have the option of specifying that certain change numbers are valid
or invalid for the explosion (direct assignments).

System Response

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

How to fix this error?

If you want to create a production order with a particular parameter
variant, first, maintain this parameter variant in the sales order item
and then create the production order.

Error message extract from SAP system. Copyright SAP SE.