After having deleted a large folder I get a plasma notification that the folder has been deleted and I also get an "open" button that leads to an error because the folder obviously doesn't exist anymore.
Thanks for the bug report, but those notifications are not part of Dolphin. I think that this comes from KIO.
*** Bug 311728 has been marked as a duplicate of this bug. ***
I'm experiencing this in KDE 4.10 beta 2.
*** Bug 317300 has been marked as a duplicate of this bug. ***
I think this would qualify as an extramile bug.
To mark this as an extramile bug, enter in Blocks field extramile.
Works for me in KDE Frameworks 5.45.