You get this error when displaying a page:
HTTP Error 404 - Page Not Found
In general there is nothing specific about the 404 errors and Iron Speed Designer. Microsoft Internet Information Server (IIS) reports these errors when it cannot find a page to display or is not configured properly.
There are a variety of causes for this error:
Make sure that Microsoft .NET Framework is installed on your deployment machine. See Configuring the Microsoft .NET Framework for instructions.
The application was deployed to the webroot folder. If you deployed to the webroot folder, you need to update your application’s Web.config file (<App Folder>\Web.config) with keys that reflect this change.
See Deploying to Webroot for details.
If you deployed to something other than the webroot folder, make sure you have created a virtual directory. You can create a virtual directory by going to the Internet Information Services under Administrative Tools from the Windows Start menu. Expand your website and create a virtual directory to point to the folder where your application resides.
See Creating a Virtual Directory for Your Application for details.
Check to make sure that the Windows Firewall does not block HTTP requests. Go to the Control Panel, click on Windows Firewall, go to the Advanced tab, click on Settings under the Network Connection Settings, and make sure Web Server (HTTP) is selected. This is typically the problem when you can access the application locally on the same machine, but not from another machine.
Make sure the ASPNET account has permissions to the folder containing your application. Your ASPNET user needs full permissions in order for your application to run properly.
See ASP.NET User Does Not Have Permissions to Your Application Folder for instructions on granting access permissions.
See Virtual Directory on Microsoft IIS Does Not Allow Anonymous Access for instructions on allowing anonymous access.
Beyond, these reasons, there could be other reasons as well that you are getting 404 errors. Here are some websites that you might also scan to see in case the above items do not help resolve the issue.
http://www.vbip.com/books/1861005040/chapter_5040_13.asp
Your application can provide additional debugging information that can help diagnose this problem.
Change the CustomErrors setting in your Web.config file to see the detailed error message. Specifically, change:
<customErrors mode="On" />
to:
<customErrors mode="Off" />
Then, run your application again. This will give more detailed error messages as to the problem you are having.
Configuring the Microsoft .NET Framework
Creating a Virtual Directory for Your Application
Part VII: Troubleshooting Applications
Application Runs But No Data is Displayed