Oracle Solution for Error ora-30398

ORA-30398: illegal JOIN KEY clause

What triggered the Error:

A JOIN KEY clause was specified that did not conform to certain requirements. A JOIN KEY clause connecting a child level with its non-immediate ancestor level is allowed only when that child level and its ancestor level satisfy the following conditions: *1. The immediate parent of the child level must be a skip level. *2. The child level cannot be a skip level. *3. The ancestor level must be a non-skip level. *4. The ancestor level must be the nearest non-skip level to the child level in the hierarchy.

What should we do to fix it:

Modify the JOIN KEY clause so that it satisfies the conditions mentioned above.