phpBB : Critical Error

Error creating new session

DEBUG MODE

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

INSERT INTO forum_sessions (session_id, session_user_id, session_start, session_time, session_ip, session_page, session_logged_in, session_admin) VALUES ('23b1563a5fd892f082e544361884d872', -1, 1539679909, 1539679909, '36c6d41e', 2, 0, 0)

Line : 187
File : sessions.php