$re = '/<Entry>((?!<\/Entry>).)*<\/Entry>/s';
$str = '<Entry>
<Type>Unknown</Type>
<DateTime>11/28/2017 11:19:49.652</DateTime>
<Level>Exception</Level>
<Host>CNTX-PROD-WEB-A</Host>
<ThreadID>139</ThreadID>
<Request.URL>https://bonnier.magazine-services.net:44314/CS/Account.aspx?accountid=3622083</Request.URL>
<Comment>Subscript =3420512 - Has an invalid state. The publication is ceased, but the subscription is not canceled.</Comment>
<ExceptionMessage>Issue with subscription: 3420512</ExceptionMessage>
</Entry>
<Entry>
<Type>Unknown</Type>
<DateTime>11/28/2017 11:19:49.652</DateTime>
<Level>Exception</Level>
<Host>CNTX-PROD-WEB-A</Host>
<ThreadID>139</ThreadID>
<Request.URL>https://bonnier.magazine-services.net:44314/CS/Account.aspx?accountid=3622083</Request.URL>
<Comment>Subscript =3420512 - Has an invalid state. The publication is ceased, but the subscription is not canceled.</Comment>
<ExceptionMessage>Issue with subscription: 3420512</ExceptionMessage>
</Entry>
<Entry>
<Type>Unknown</Type>
<DateTime>11/28/2017 11:19:49.652</DateTime>
<Level>Exception</Level>
<Host>CNTX-PROD-WEB-A</Host>
<ThreadID>139</ThreadID>
<Request.URL>https://bonnier.magazine-services.net:44314/CS/Account.aspx?accountid=3622083</Request.URL>
<Comment>Subscript =3420512 - Has an invalid state. The publication is ceased, but the subscription is not canceled.</Comment>
<ExceptionMessage>Issue with subscription: 3420512</ExceptionMessage>
</Entry>';
preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);
// Print the entire match result
var_dump($matches);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php