Task/request &1 does not exist in system &2

What causes this issue?

Request &V1& was not found in system &V2&.

System Response

The request cannot be displayed in system &V2&.

How to fix this error?

If you want to display the request, log on to the system in which the
request was created or log on to a system into which it was already
imported.
If you want to display the export or import logs of the request, this
can be done in you local system (depending on your transport landscape).
To do this, follow the procedure below:
Call transaction SE09 in your local system.
Choose "Goto -> Transport Organizer (Extended View)".
Choose the "Single Display" tab.
Enter the request in the "Request/Task" field.
Choose "Logs".

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.