Discuz! info: MySQL Query Error

Time: 2018-9-21 4:38am
Script: /pm.php

SQL: SELECT * FROM cdb_crons WHERE available>'0' AND nextrun<='1537475901' LIMIT 1
Error: Table 'amsforum_forumdb.cdb_crons' doesn't exist
Errno.: 1146

Similar error report has beed dispatched to administrator before.