Set & does not exist

What causes this issue?

The set &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.

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 the error occurred.

Error message extract from SAP system. Copyright SAP SE.