TYPO3 PHP更新到7.0 | 日志说“Switch语句可能只包含一个默认子句”

I want to update PHP from 5.6 to 7.0 but I get a 500 HTML Error and in the logs it says:

[Mon Oct 22 09:42:14 2018] [-:error] [pid 12784] [client 5.158.158.123] [host www.mydomain.de] PHP Fatal error:  Switch statements may only contain one default clause in /is/htdocs/wp12731216_QEO0DONMD6/www/typo3conf/ext/dam/lib/class.tx_dam_db.php on line 547

So I looked into the file and found as it says a dublicate default: statement:

if ($appendType = $TCA['tx_dam']['columns'][$field]['config']['appendType']) {
    $appended = true;
    switch($appendType) {
        case 'space':
            $rowUpdate[$field] = trim($row[$field].' '.$value);
            break;
        case 'newline':
            $rowUpdate[$field] = $row[$field].($row[$field]?"
":'').$value;
            break;
        case 'comma':
            $rowUpdate[$field] = $row[$field].($row[$field]?', ':'').$value;
            break;
        case 'charDef':
            default:
            list($type, $appendChar) = explode(':', $appendType);
            $rowUpdate[$field] = $appendChar.$value;
            break;
        default:
            $appended = false;
            break;
    }
}

So my Question is, is there a solution? Can I just edit this file and remove the last default statement? Or should I update to a different PHP Version?

So I found the solution myself after a while...

I had to update the Extension where the file with the error comes from.