Could not process object, type 'Entity Folder' has no role 'classifications'

Hi,

When I'm trying to assign a classification to Custom objects via web its working fine, but when I'm trying to do the same with Rest Api its not working and giving me below error.

Could not process object, type 'Entity Folder' has no role 'classifications'

While I'm invoking same request for Managed Objects its also working fine. Does anybody has any idea about how to assign classification on custom objects via rest api ?

Its a blocker right now for me.