Discuz! info: MySQL Query Error

Time: 2018-8-14 4:52pm
Script: /index.php

SQL: INSERT INTO cdb_sessions (sid, ip1, ip2, ip3, ip4, uid, username, groupid, styleid, invisible, action, lastactivity, fid, tid)
VALUES ('1E9kLM', '54', '80', '102', '170', '0', '', '7', '2', '', '1', '1534236773', '', '')
Error: Incorrect integer value: '' for column 'invisible' at row 1
Errno.: 1366

Similar error report has beed dispatched to administrator before.