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 ('ae012748adbc2bc2bfa9a1fe96baa6e4', -1, 1550515088, 1550515088, '36d23d29', 28, 0)

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