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 ('f69224493d1249302fc91f1236f35a65', -1, 1558648964, 1558648964, '3417ea07', -4, 0, 0)

Line : 187
File : sessions.php