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 ('78ae29e193cf043f6c3024e1a44f62e1', -1, 1711652877, 1711652877, '36a0f32c', 6, 0, 0)

Line : 187
File : sessions.php