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 ('d95abb54d5e93620a731614232cf3c32', -1, 1566297945, 1566297945, '22cca94c', -4, 0, 0)

Line : 172
File : sessions.php