In order for the page to render correctly, add the following to the web.config file:
<location path="utility">
<system.web>
<authorization>
<allow users="*" />
</authorization>
</system.web>
</location>
<location path="themes">
<system.web>
<authorization>
<allow users="*" />
</authorization>
</system.web>
</location>
<location path="cfs-file.ashx">
<system.web>
<authorization>
<allow users="*" />
</authorization>
</system.web>