Discuz! info: MySQL Query Error

Time: 2018-8-17 1:39am
Script: /pm.php

SQL: SELECT * FROM cdb_crons WHERE available>'0' AND nextrun<='1534441151' LIMIT 1
Error: Table 'amsforum_forumdb.cdb_crons' doesn't exist
Errno.: 1146

Similar error report has beed dispatched to administrator before.