If I attempt to delete a content node (which I've just created - unsure if that matters), I get a success confirmation and a warning that the deletion failed at the same time.

To reproduce:

1. Add a new content node
2. Select it, then "delete item"
3. Confirm the deletion
   -> We get a "Deletion successful" notification and a warning of a failure of the long-running delete task at the same time.

The failure in this test was actually to a non-configured subscriber.