phpBB : Critical Error

Error creating new session

DEBUG MODE

SQL Error : 1062 Duplicate entry '-1' for key 'session_user_id'

INSERT INTO oka_phpbb_sessions (session_id, session_user_id, session_start, session_time, session_ip, session_page, session_logged_in) VALUES ('81cd37c7b5b01fc96ac915902c2cb5e2', -1, 1550507363, 1550507363, '22e473d8', -9, 0)

Line : 184
File : /home/c128/public_html/talk/includes/sessions.php