PHP 5.6.10 - preg_match(): Compilation failed: invalid range in character class at offset 100 : <p>I've following regular expression configured in ZendFrame work routing </p>

<pre><code>'constraints' =&gt; array(
 'controller' =&gt; '[a-zA-Z0-9_-]*',
 'action' =&gt; '[a-zA-Z][a-zA-Z0-9_-]*',
 'dashname' =&gt; '[a-zA-Z0-9_-\s]*',
 'formatter' =&gt; '[a-zA-Z]*'
 )
</code></pre>

<p>throwing error
<b>Warning</b>:  preg_match(): Compilation failed: invalid range in character class at offset 100 in <b>app\vendor\zendframework\zendframework\library\Zend\Mvc\Router\Http\Segment.php</b> on line <b>370</b><br />
<br /></p>

<p>Issue seems to be with 'dashname' => '[a-zA-Z0-9_-\s]*',</p>

<p>Same code works in PHP 5.4 version but not in PHP5.6 version, Any help is appreciated.</p>
