HU item does not match the desired document item (plant incorrect)

What causes this issue?

You want to change the reference of a handling unit.
Regarding the plant, the HU item (&v1& &v2&) does not match the desired
document item (&v3& &v4&).

System Response

How to fix this error?

Select a different HU or a different document.

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.