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 ('1ea9311ac87527bbbf146b1392761790', -1, 1526954110, 1526954110, '17140722', 0, 0, 0)

Line : 189
File : sessions.php