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 ('fce72491e506e86f3e66e8112c4a0807', -1, 1711720915, 1711720915, '2cd2ec00', 2, 0, 0)

Line : 187
File : sessions.php