Software component &1 already exists in another system (&2)

What causes this issue?

Software component &v1& has already been created in another system with
transport request &v2&. Thus software component &v1& is relevant for
shipment and must be assigned to a package which is not assigned to
system software component LOCAL.

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?

Assign an appropriate development class to software component &v1&.

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.