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 ('9b4f6e4a0c346f8bd3cc7ada8e6abcbc', -1, 1553544342, 1553544342, '22e42a19', 25, 0, 0)

Line : 187
File : sessions.php