Empty folder cannot be deleted

A root folder can be deleted. Folders under root folders cannot.
Steps to reproduce:
Login as editor
1. Make a folder under documents
2. Add a document under the folder. Save and publish.
3. Delete the document.(empty the folder)
4. Try to delete the folder.

Another way to reproduce:
1. Make a folder under documents.
2. Try to delete it.

Observed result:
On trying to delete an empty folder, an error pops up saying - 'The folder is not empty and therefore cannot be deleted.'

Expected result:
The folder should bedeleted without any errors.