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 ('b247d4afa8ae1c416d7e2f41c5eb5fc5', -1, 1550513738, 1550513738, '36d23d29', 0, 0)

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