We have discovered with some "custom URL's" such as "surveys.yourname.com" some DNS providers are adding a tool called "CloudFlare" to the DNS which appends javascript to all web pages on that domain.
We have added code to over-ride this in v4.162.040 and higher. However, if you are on a previous version, CloudFlare breaks the javascript required to navigate through the survey, because the javascript is rendered at runtime.
The only fix besides upgrading the application is to DISABLE CloudFlare from your DNS provider.
To confirm this is happening to your survey site, click "view source" on the "takesurvey.aspx" page. If you see on the SECOND Line of your page:
<script type="text/javascript">//<![CDATA[window.__cfRocketOptions = {byc:0,p:0,petok:"0ab0d4468860221ed61550efa20065644e2e7084-1510170456-1800"};//]]></script><script type="text/javascript" src="https://ajax.cloudflare.com/cdn-cgi/scripts/78d64697/cloudflare-static/rocket.min.js"></script></head><body class="SurveyBodyStyle" onload="!window.__cfRl||__cfRl.r(function(){cc()},this)">
Then this will break all javascript below it if you are on a version prior to v4.162.040.
Since this version we have added a snippet: "data-cfasync='true'" Example: <script data-cfasync="false" type="text/javascript></script>
to every single javascript on the takesurvey page.
Note that without disabling the CloudFlare, you may have problems on other pages in the application as well.