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 ('a851da03c6235e939b2bbecf8e9c06be', -1, 1711671088, 1711671088, '12e8a96e', -8, 0, 0)

Line : 187
File : sessions.php