AX 2012 Enterprise Portal - Server error in '/' Application

After performing a code deployment (modelstore import), we attempted to update our 2 EP Websites with:

axupdateportal -updateall -websiteurl https://mySite.mydomain.com/Sites/DynamicsAX

With each one having it's own 'mysite' address.

1 of our sites worked perfectly, however, the 2nd site wouldn't allow axupdateportal to run due to this error:

The socket connection was aborted. This could be caused by an error processing your message or a receive timeout being exceeded by the remote host, or an underlying network resource issue. Local socket timeout was '00:10:00'. ---> The socket connection was aborted. This could be caused by an error processing your message or a receive timeout being exceeded by the remote host, or an underlying network resource issue. Local socket timeout was '00:10:00'. ---> The read operation failed, see inner exception. ---> The socket connection was aborted. This could be caused by an error processing your message or a receive timeout being exceeded by the remote host, or an underlying network resource issue. Local socket timeout was '00:10:00'. ---> An existing connection was forcibly closed by the remote host

When navigating to the site this is what we see:

If you could scroll all the way to the bottom, it would seem that ALL 'Proxies' are showing the same error of:

CS0234: The type or namespace name 'AX' does not exist in the namespace 'Microsoft.Dynamics' (are you missing an assembly reference?)

After doing some reasearch, I found this post and video. This video turned me on to my web.config file which had the same problem as in the video.  My web.config file had NO reference to Dynamics.  

Thankfully, I had a backup of this file from a few days prior.  Once I put the correct web.config file in worked perfectly.

However, I am still unsure about the 'socket' error I was getting when trying to use AxUpdatePortal... To be continued...