Nope not that I see. I don't ever turn off IIS when upgrading for QA purposes. I don't even close open browsers or tabs pointing to sites I'm upgrading

That said; are you able to open the web.config on all 3 sites? Can you change the "customErrors mode ="Off" to customErrors ="ON" 

You may also need to set "Compliation Debug to "True" if you don't get anything from changing just the customErrors

If you can do that then re-hit the sites you should get a verbose error message in the browser instead of the default "something bad happened do this" message.

Post the error message(s) back to this thread. You can scrub any corporate or PII off the messaging if you have any privacy concerns about publicly posting the complete message.

Hi Ken,

I have changed the settings that you suggested :-

   
and
 
   

I now get the following error :-

Server Error in '/' Application.

Description: The application attempted to perform an operation not allowed by the security policy.  To grant this application the required permission please contact your system administrator or change the application's trust level in the configuration file.

Exception Details: System.Security.SecurityException: Request for the permission of type 'System.Web.AspNetHostingPermission, System, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089' failed.

Source Error:

Security Exception

Version Information: Microsoft .NET Framework Version:2.0.50727.4927; ASP.NET Version:2.0.50727.4927

Roger;

Let's deal with the fatal error issue first and see what issues remain after the sites are up and running.

From the error message you posted you have some sort of Trust issue going on with the site.

Are you on a Hosting provider?

What Trust level do they operate at for .Net sites?

What is the trust setting in the web.config files?

Out of the box DNN Trust is set as follows:

    <!-- set code access security trust level - this is generally set in the machine.config
    <trust level="Medium" originUrl=".*" />
    -->

You may need to change it to:

    <!-- set code access security trust level - this is generally set in the machine.config     -->
    <trust level="Medium" originUrl=".*" />
  
 

I'm thinking the way you did the copy did not merge the web.config files so you've ended up with a default web.config setup.

I think you need to reconcile the web.config Trust settings between your 5.2.2 site web.config settings; the upgraded 5.2.3 web.config settings and what your hosting provider allows for Trust.