SQL info: MySQL Query Error

Time: 2019-11-23 7:56am
Script: /newslist.php

SQL: INSERT INTO t_session (sid,uid,islogin,isadmin, updated, sessiondata ) VALUES ('c81a3b','','','', '1574466972', 'a:0:{}')
Error: Duplicate entry 'c81a3b' for key 'PRIMARY'
Errno.: 1062