I think there is bug in Osclass core for long long time, but started to be issue now (for some reason).
In oc-includes/osclass/model/LatestSearches.php, try to replace your getSearches function with:
public function getSearches($limit = 20, $sort = 'd_date') {
$this->dao->select('s_search, MAX(d_date) as d_date, COUNT(s_search) as i_total');
$this->dao->from($this->getTableName());
$this->dao->groupBy('s_search');
$this->dao->orderBy($sort, 'DESC');
$this->dao->limit($limit);
$result = $this->dao->get();
if($result == false) {
return false;
}
$data = $result->result();
$output = array();
if(is_array($data) && count($data) > 0 && osc_latest_searches_restriction() <> 0 && osc_latest_searches_words() <> '') {
foreach($data as $row) {
$word = osc_latest_search_filter($row['s_search']);
if($word <> '') {
$output[] = $row;
}
}
return $output;
}
return $data;
}