Webhook Subscription Not Working.

Hi, i have implemented webhooks successfully and everything was working fine. I could subscribe, remove and fetch the current subscriptions from my api. This has been working for over 3 months. Now when i go to subscribe i get this error response.

<head>
<meta http-equiv="Content-Type" content="text/html;charset=ISO-8859-1"/>
<title>Error 500 </title>
</head>
<body>
<h2>HTTP ERROR: 500</h2>
<p>Problem accessing /restapi/v1.0/subscription. Reason:
<pre>    org.springframework.web.util.NestedServletException: Handler dispatch failed; nested exception is java.lang.NoSuchMethodError: com.google.common.net.HostAndPort.getHost()Ljava/lang/String;</pre></p>
<hr />
</body>
</html>

I don't understand what to fix and i'm at a loss of where to dig because this was all working before.

Im using the php backend framework and my code looks like this.

$params = array(
                'eventFilters' => array(
                    '/restapi/v1.0/account/~/extension/~/message-store/instant?type=SMS',
                    '/restapi/v1.0/account/~/extension/~/telephony/sessions'
                 ),
                'deliveryMode' => array(
                    'transportType' => "WebHook",
                    'address' => $address
                ));
$resp = $platform->post('/subscription', $params);

Any help would be greatly appreciated, thank you for your time.