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 ('080f2a723897a929af3ed64b35be07dc', -1, 1728522012, 1728522012, '2cc05fa1', -4, 0, 0)

Line : 172
File : sessions.php