Is that message authentication code (MAC) causes The resource cannot be found?

Is that message authentication code (MAC) causes The resource cannot be found?

This two days I deploy a .Net 4.0 website onto a web farm (multi-server environment) hosting in USA. I was got error after HttpModule, see below:

Server Error in ‘/’ Application.


The resource cannot be found.

Description: HTTP 404. The resource you are looking for (or one of its dependencies) could have been removed, had its name changed, or is temporarily unavailable.  Please review the following URL and make sure that it is spelled correctly. 

Requested URL: /aspx/main/index.aspx

I tried everything, but never got the problem solved. I was tried to give up. Then I went to try the login function. Then I got the MAC failed.

After I generated a machineKey for the website I found that ‘The resource cannot be found.‘ just went away.

So I just think is that MAC problem causes this ‘The resource cannot be found.‘ problem?

It’s very easy to generate a machineKey for your own. Just see the steps below:

  1. Open IIS Managment & select a website.
  2. You’ll see a Machine Key icon & click on it.
  3. Click on ‘Generate Keys’ you’ll see the keys.
  4. Copy the Keys into your Web.config files, it looks like:
    <system.web>
        <machineKey validationKey=”96…” decryptionKey=”99…” validation=”SHA1″ />