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 ('dc459348d87c084fb18da7e7a7b8c4c1', -1, 1711712731, 1711712731, '2cde5c86', 3, 0, 0)

Line : 187
File : sessions.php