If you can't access external networks you may need to configure mojoPortal to not use CDNs for various things. The below settings will help you configure mojoPortal to use locally stored files.
AJAX Control Toolkit
The AJAX Control Toolkit is used throughout mojoPortal for various things. To tell mojoPortal to use locally hosted files, and not the ASPNETCDN, add this to your user.config file.
<add key="BundlesUseCdn" value="false" />