Issues with running remote MVC app within local asp page - asp.net-mvc

Question

I have a classic asp site, and an MVC web app. I have both of them hosted locally as localhost in my dev environment. I also have both of them set up on a remote server.
Below is a list of URLs of my apps:
classic asp site hosted locally: http://localhost/AspAppName/
classic asp site hosted on remote server (IIS): http://ServerName/AspAppName/
MVC web app hosted locally: http://localhost/MvcAppName/Dir/SubDir
MVC web app hosted on remote server (IIS): http://ServerName/MvcAppName/Dir/SubDir
What I am trying to do is have my MVC app ran within iframe placed on one of the pages of my classic asp site.
when I run my local version of MVC app within iframe of my locally ran classic asp site, everything works. In such case I use "http://localhost/MvcAppName/Dir/SubDir" as the URL to execute within my iframe and the iframe is on "http://localhost/AspAppName/SomePage.asp"
when I locally run my remote version of MVC app within iframe of my locally ran classic asp site, I get the following error:
"This content cannot be displayed in a frame.
To help protect the security of information you enter into this website, the publisher of this content does not allow it to be displayed in a frame"
In such case I use "http://ServerName/MvcAppName/Dir/SubDir" as the URL to execute within my iframe and the iframe is on "http://localhost/AspAppName/SomePage.asp"
The error shows up in IE. In Firefox and Chrome, the iframe area just ramains blank.
Just for testing purposes and to see if these are some cross-domain limitations/settings I tried putting my classic asp site hosted on remote server (http://ServerName/AspAppName/RandomPage.asp) within iframe of my classic asp site hosted locally (http://localhost/AspAppName/SomePage.asp). In such case, I do not see any errors and the local asp site displays iframe content with remotely hosted asp page without any issues.
Here is some application pool information from IIS on my local machine:
MvcAppName: .NET CLR version: v4.0, Managed Pipeline Mode: Integrated; Identity: ApplicationPoolIdentity
AspAppName: .NET CLR version: v2.0; Managed Pipeline Mode: Classic; Identity: NetworkService (!, ?)
Here is some application pool information from IIS on my remote server:
MvcAppName: .NET CLR version: v4.0, Managed Pipeline Mode: Integrated; Identity: ApplicationPoolIdentity
AspAppName: .NET CLR version: v2.0; Managed Pipeline Mode: Classic; Identity: ApplicationPoolIdentity (!, ?)
I strongly appreciate any advice on what might be causing my issue with nesting my remotely ran MVC app within iframe of my locally ran asp site.

Answer 1

Sounds like you need to return an X-Frame-Options header from the site that cannot be displayed in the iframe. This page shows the available options and how to set it up in various servers, including IIS.
https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/X-Frame-Options

Answer 2

It turned out the X-Frame-Options setting was being overwritten automatically. To turn it off, I had to add the following line to Application_Start in the Global.asax.cs.
AntiForgeryConfig.SuppressXFrameOptionsHeader = true;