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 ('933f7bec59d8c44d4acb23b4ebf2fe06', -1, 1711707713, 1711707713, '03ec937a', 6, 0, 0)

Line : 187
File : sessions.php