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 ('278b4f888c17055f7549cc1c47cca7ad', -1, 1713483713, 1713483713, '12760c65', -9, 0, 0)

Line : 187
File : sessions.php