phpBB : Critical Error

Error creating new session

DEBUG MODE

SQL Error : 1062 Duplicate entry '0' for key 'session_user_id'

INSERT INTO phpbb_sessions (session_id, session_user_id, session_start, session_time, session_ip, session_page, session_logged_in, session_admin) VALUES ('8c4003d4dd33d9f04f4f87e3188e4b7a', -1, 1539928640, 1539928640, '36e11a2c', 58, 0, 0)

Line : 187
File : sessions.php