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 ('f26e9efb3d15f9c3a20807cc6f8011f2', -1, 1757352916, 1757352916, 'd849d8bb', -9, 0, 0)

Line : 187
File : sessions.php