Can't add foreign key PostgreSQL

Question

Can't add foreign key to table. DB Graph: https://pp.vk.me/c638520/v638520058/11d8a/yqKLEPtqNOk.jpg

Code:

ALTER TABLE public.row DROP CONSTRAINT statement_section_id_fk;
ALTER TABLE public.row
ADD CONSTRAINT statement_section_id_fk
FOREIGN KEY (row_id) REFERENCES statement_section (section_id) ON DELETE CASCADE ON UPDATE CASCADE;

No alert, no exceptions, just https://pp.vk.me/c638520/v638520058/11d83/ymwwrM1udhA.jpg