Why am I getting error 500.0 in when using IIS Express (significant debug info included)

Question

I created a blank MVC 3 application on VS2010 SP1, and set the app to use IIS Express. When I debug, I get error 500.0 (0x80070585)

I am able to succesfuly run the app using the VS dev server

I have set the app directory to Full Permissions for Everyone, just to eliminate all possibility of security issues. I have further verified that IIS express is able to hit the web.config by confirming it using SysInternals ProcMon. ProcMon does not show the IISExpress process attempting to read from any other files in my application directory.

I have followed the suggestions in the following question, but it does not give me any better information. HTTP 500 Internal Error - IIS websites

No logs are generated in the IISExpress directory in either the Logs or TraceLogs directory, but a log is created in Temp, however it is not very useful.

Successfully registered URL "http://localhost:62017/" for site "MvcApplication1" application "/"
Registration completed for site "MvcApplication1"
Request ended: http://localhost:62017/ with HTTP status 500.0
Request ended: http://localhost:62017/ with HTTP status 500.0
Request ended: http://localhost:62017/ with HTTP status 500.0

There are no messages I am able to find in the Event Viewer

**Updates : ** Disabled firewall, no change Ran IISExpress via command line, no change

Answer 1

I had the same issue last week, the app running perfect in dev web server from VS Studio. But in IISExpress anytime HTTP Error 500. My solution on this time was:

• close VS Studio - solution set with IISExpress
• got to: /Document/IISExpress/config/ in your profile
• rename or delete applicationhost.config
• open your solution in VS Studio
• a Dialog will fire up from IISExpress - this will set a fresh config.
• try to run your web app

Answer 2

You may have some mime code in the Web.Config file like this:

<mimeMap fileExtension=".svg" mimeType="image/svg+xml" />

if so, you should remove mimeMap before adding like this:

.
..
...
....
  </system.web>
  <system.webServer>
    <staticContent>
      <remove fileExtension=".svg" />
      <mimeMap fileExtension=".svg" mimeType="image/svg+xml" />
    </staticContent>
  </system.webServer>

....
...
..
.