The variable & does not exist

What causes this issue?

The variable &v1& which is used in report &v2&, does not exist in the
current client. Possible cause of error: The report was imported from
another client or from a different system without dependent objects.

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

System Response

The function cannot be executed.

How to fix this error?

Import the report once again with the dependent objects
(<DS:TRAN.GR39> import report </>). If the error still occurs, contact
the SAP Hotline and send this long text as well as detailed information
describing the circumstances in which this error occurred.

Error message extract from SAP system. Copyright SAP SE.