phpBB : Critical Error

Error creating new session

DEBUG MODE

SQL Error : 1062 Duplicate entry '-1' 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 ('427e4f5268452abd3b2c8c9bdc7b74d9', -1, 1558392435, 1558392435, '36a3147b', 4, 0, 0)

Line : 187
File : sessions.php