Request & is not a workbench request or customizing request

What causes this issue?

You want to assign task &V2& to request &V1&.
You can reassign to a Workbench or Customizing request only. &V1& is
neither a Workbench nor a Customizing request.

System Response

The function terminates.

How to fix this error?

Repeat the function with a valid request. Use input help (F4) to search
for a request.

Error message extract from SAP system. Copyright SAP SE.