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 ('1cc87702a9e434c89a8181b9ba402cfc', -1, 1711711372, 1711711372, '2cc8bf92', -4, 0, 0)

Line : 187
File : sessions.php