Item Category Assignments Can Only Be Made At Leaf Nodes Of A Category Hierarchy

ERROR:
Item category assignments can only be made at leaf nodes of a category hierarchy.

STEPS:
The issue can be reproduced at will with the following steps:

Master items->Tools->Categories, when we trying to assign a new category.



SOLUTION:


To fix the current data


Run the below 2 scripts to identify the records

select structure_id, category_id,concatenated_segments
from mtl_categories_b_kfv
where summary_flag = 'Y';

SELECT CATEGORY_SET_ID, CATEGORY_SET_NAME , STRUCTURE_ID
FROM mtl_category_sets_vl;

Then, Use the below datafix script by inserting the structure_id

update mtl_categories_b
set summary_flag = 'N'
where summary_flag = 'Y'
and structure_id =&structure_id;