SYMPTOMS

When trying to access the webmail interface the following error is displayed in the browser:

Server Error in '/MEWebMail' 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: /MEWebMail/eurl.axd/422d6943116ab041a86bb2916824f302

Version Information: Microsoft .NET Framework Version:2.0.50727.42; ASP.NET Version:2.0.50727.210

CAUSE

This error occurs because when ASP.NET detects that a web site is configured to use ASP.NET 4, a native component of ASP.NET 4 passes an extensionless URL to the managed portion of ASP.NET for further processing. However, if virtual directories that are below an ASP.NET 4 web site are configured to use ASP.NET 2.0, processing the extensionless URL in this way results in a modified URL that contains the string "eurl.axd". This modified URL is then sent to the ASP.NET 2.0 application. ASP.NET 2.0 cannot recognize the "eurl.axd" format. Therefore, ASP.NET 2.0 tries to find a file named eurl.axd and execute it. Because no such file exists, the request fails with an HttpException exception.

WORKAROUND

Option 1

If ASP.NET 4 is not required in order to run the Web site, remap the site to use ASP.NET 2.0 instead.

Option 2

If ASP.NET 4 is required in order to run the web site, move any child ASP.NET 2.0 virtual directories to a different web site that is mapped to ASP.NET 2.0. Or alternatively configure host headers under the MailEnable web mail website. Information how to create host headers under the MailEnable web mail website can be found within the MailEnable documentation.

Option 3

If it is not practical to remap the web site to ASP.NET 2.0 or to change the location of a virtual directory, explicitly disable extensionless URL processing in ASP.NET 4. Use the following procedure:

1. In the Windows registry, open the following node:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\ASP.NET\4.0.30319.0

1. Create a new DWORD value named EnableExtensionlessUrls.
2. Set EnableExtensionlessUrls to 0. This disables extensionless URL behavior.
3. Save the registry value and close the registry editor.
4. Run the iisreset command-line tool, which causes IIS to read the new registry value.

http://www.asp.net/%28S%28ywiyuluxr3qb2dfva1z5lgeg%29%29/learn/whitepapers/aspnet4/breaking-changes#0.1__Toc256770153