function getSemanticRelevantKeywords($keyword){
    $results = array();
    $html = file_get_html("http://www.semager.de/api/keyword.PHP?q=". urlencode($keyword) ."&lang=de&out=html&count=2&threshold=");
    foreach($html->find('span') as $e){
            $results[] = $e->plaintext;
    }
    return $results;
}

但是当我输出结果时我收到这个错误：

Fatal error: Call to a member function find() on a non-object in
/var/www/vhosts/efamous.de/subdomains/sandBox/httpdocs/getNewTrusts.PHP
on line 25

(第25行是foreach循环),奇怪的是它输出所有内容(至少看似完整),但我仍然收到错误,无法弄清楚为什么.