phpBB : Critical Error

Error creating new session

DEBUG MODE

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

INSERT INTO forum_sessions (session_id, session_user_id, session_start, session_time, session_ip, session_page, session_logged_in, session_admin) VALUES ('0f23efc2a9e95c5219be483a7c69ef75', -1, 1539948104, 1539948104, '36e11a2c', -8, 0, 0)

Line : 187
File : sessions.php