Could not locate delivery &1

What causes this issue?

Delivery &V1& could not be found.

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

System Response

How to fix this error?

Leave transaction VSB1, and call it up again. If the delivery really
exists and the error continues to exist after calling transaction VSB1
again, contact SAP.

Error message extract from SAP system. Copyright SAP SE.