When deleting a huge file or folder, a desktop notification is shown when the task has finished. This notification is the same that appears when a file has been copied, i.e. it also has an "Open" button to open the destination. This is pretty useless on file deletion notifications since that location doesn't exist anymore after it has been deleted.
So it's not surprising that clicking that button shows an error dialog "Unable to run the command specified. The file or folder file://foobar does not exist."
There should be no "Open" button.
*** This bug has been marked as a duplicate of bug 311824 ***