phpBB : Critical Error

Error creating new session

DEBUG MODE

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

INSERT INTO docttorrdiscluc_sessions (session_id, session_user_id, session_start, session_time, session_ip, session_page, session_logged_in, session_admin) VALUES ('64cb489cccf7a23d8e637b6c4eb7e128', -1, 1547891782, 1547891782, '22cbd574', 1, 0, 0)

Line : 190
File : sessions.php