Extended Classification issue

Trying to set up a small tree. I could build the tree with 6 classes, and 10 attributes with attribute inheritance from parent to child class. But I am not able to Restrict Selection To Only Leaf Classes
Restrict Selection To Only Leaf Classes set to true
Restrict Selection To A Single Class set to true
Error : apply "Restrict Selection to only Leaf Classes" preference for the "XXX" xClassificationTree because there are items with conflicted classification.
Anyone saw this before?
  • I have made sure I do not have any parts/docs/cad classified yet (one part was classified few days back, have deleted the classification for it). Could fix this by running some db queries and finding 3 older versions still classified in parent class, removed them and its working now