found in version 12.1.5
in <SEPM>\Inetpub\Reporting\Dashboard\securitystatus.php
line 1626
repair the 'from' and 'where' parameters in:
$queryMachinesNotScanned = $queries->getTotalNotScanedQuery($dashboard_sqlwhere_inventory, $dashboardsqlwhere, $millisAgo);
result
$queryMachinesNotScanned = $queries->getTotalNotScanedQuery($dashboard_sqlfrom_inventory, $dashboard_sqlwhere_inventory, $millisAgo);