Error deleting a subcommunity

[Night Librarian]

Greetings,

My colleague accidentally created a sub-community in our DSpace 4 and wants to delete it, but when he clicks on "Delete Community", he has the following error:

org.postgresql.util.PSQLException: ERROR: constraint "com2com_child_fk" does not exist

How could it be fixed?

The community2community table has 47 rows and looks like this:

Additional information about the table:

-- Table: public.community2community
-- DROP TABLE public.community2community;
CREATE TABLE public.community2community
(
  id integer NOT NULL,
  parent_comm_id integer,
  child_comm_id integer,
  CONSTRAINT community2community_pkey PRIMARY KEY (id),
  CONSTRAINT community2community_parent_comm_id_fkey FOREIGN KEY (parent_comm_id)
      REFERENCES public.community (community_id) MATCH Unknown
      ON UPDATE NO ACTION ON DELETE NO ACTION
)
WITH (
  OIDS=FALSE
);
ALTER TABLE public.community2community
  OWNER TO postgres;

==========================================

CREATE TABLE public.community2community (
    id integer NOT NULL,
    parent_comm_id integer,
    child_comm_id integer
);

ALTER TABLE public.community2community OWNER TO postgres;
--
-- TOC entry 206 (class 1259 OID 16451)
-- Name: community2community_seq; Type: SEQUENCE; Schema: public; Owner: postgres
--

CREATE SEQUENCE public.community2community_seq
    START WITH 42
    INCREMENT BY 1
    NO MINVALUE
    NO MAXVALUE
    CACHE 1;