phpBB : Kritischer Fehler

Error creating new session

DEBUG MODE

SQL Error : 1062 Duplicate entry '-1' for key 'session_user_id'

INSERT INTO abnehm_bb_sessions (session_id, session_user_id, session_start, session_time, session_ip, session_page, session_logged_in, session_admin) VALUES ('988ad5009eabc4111ad90d43b5ac7f50', -1, 1501086506, 1501086506, '36509e7f', 5, 0, 0)

Line : 179
File : sessions.php