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 ('d8988eb0e60787c3a5c93d5211563cf6', -1, 1638359884, 1638359884, '34cda768', -6, 0, 0)

Line : 187
File : sessions.php