The skript actually created the "New Base Folder" below the absolute root. And as you say, I set the local root = abolute root. So "New Base Folder" should not be a root folder at all. The DMX tree looks as follows:
- Document Exchange
+ Project 1
+ Project 2
+ New Base Folder
However I still can't delete the "New Base Folder" because there is no menu available for this folder (neither context menu nor head menu). Is there a way to remove the folder manually in the DB and/or server?