Fatal error - badly need help

    /**
     * Always ensure that the title strips any HTML/MODX tags
     * @param string $k
     * @param string|null $format
     * @param string|null $formatTemplate
     * @return mixed
     */
    public function get($k, $format = null, $formatTemplate= null) {
        $v = parent::get($k,$format,$formatTemplate);
        switch ($k) {
            case 'title':
                $v = html_entity_decode($v);
                $v = $this->xpdo->discuss->stripAllTags($v);
                $v = strip_tags($v,'<span>');
                $v = preg_replace('@\[\[(.[^\[\[]*?)\]\]@si','',$v);
                break;
            default: break;
        }
        return $v;
    }

<p>[[!Discuss.Popular]]</p>

<ol>
<li> 
<h5><a href="/forums/thread/[[+thread]]/[[+threadname]]#dis-post-[[+post]]">[[+title]]</a></h5>
<p style='margin-top:-15px'>[[+message:strip:stripTags:ellipsis=`50`]]</p>
                    <div class="clear"></div>
</li>
</ol>

<?php
$weghalen = array(",", "/", "?", "<", ">", ";", ":", "[", "]", "{", "}", "!", "@", "#", "$", "%", "^", "&", "*", "(", ")", "_", "+", "=");
$vervangen = array(" ", ".");
 
$c = $modx->newQuery('modUser');
$c->leftJoin('modUserProfile','Profile');
$c->sortby('id','ASC');
// add column names that u want to show
$c->select(array(
    'modUser.*',
    'Profile.fullname',
    'Profile.email',
));
  
$users = $modx->getCollection("modUser",$c);
$naam[0] = 'Anoniem';
foreach($users as $user){
    $usr = $user->toArray();
 
$naam[$usr['id']] = $usr['username'];
$email[$usr['id']] = $usr['email'];
}
 
$tpl = $modx->getOption('tpl',$scriptProperties,'Forumthreads.Popular');
 
$package_path = $modx->getOption('core_path').'components/discuss/model/';
$modx->addPackage('discuss', $package_path);
$vraag = $modx->newQuery('disThread');
$vraag->sortby('replies','DESC');
$vraag->where(array(
));
$vraag->limit(5,0);
 
$regels = $modx->getCollection('disThread',$vraag);
$output = '';
 
foreach($regels as $regel){
$rglArray['post']= $regel->get('id');
$rglArray['thread']= $regel->get('thread');
$titel = strtolower($regel->get('title'));
if(substr($titel, 0,4)=="re: "){$titel = substr($titel,4);}
$titel= str_replace($vervangen, "-", str_replace($weghalen, "", $titel));
if(substr($titel,-1)=="-"){$titel = substr($titel,0,-1);}
$rglArray['threadname'] = $titel;
//$rglArray['threadname'] = $titel2;
$rglArray['title']= $regel->get('title');
$rglArray['message']= $regel->get('message');
$rglArray['author'] = $naam[$regel->get('author')];
$rglArray['createdon']= $regel->get('createdon');
$rglArray['gravatar'] = "http://www.gravatar.com/avatar/".md5(strtolower(trim($email[$regel->get('author')])))."?d=mm&s=50";
$rglArray['email'] = $email[$regel->get('author')];
$rglArray['nummer'] =$nummer;
 
$output .= $modx->getChunk($tpl,$rglArray);
}
return $output;

$package_path = $modx->getOption('core_path').'components/discuss/model/';
$modx->addPackage('discuss', $package_path);

$package_path = $modx->getOption('core_path').'components/discuss/model/';
$modx->getService('discuss', 'Discuss', $package_path);