WebApi’s {“message”:”an error has occurred”} on IIS7, not in IIS Express

asp.net-mvc-4asp.net-web-apiiis-7

I'm working with ASP.NET MVC 4 WebApi and am having a lot of fun with it running it on my local computer on IIS Express. I've configured IIS Express to serve remote machines too, and so other's in my company are using my computer as our webserver.

After deciding this was a less-than-optimal solution, we decided to put the WebApi on a remote server after installing .NET 4.5. When I use fiddler and sent a POST to a controller on my local machine it returns the correct response, yet when I change the domain to the webserver running IIS7 the same POST returns a cryptic

{"message":"an error has occurred"}

message. Anyone have any idea what could be going on?

Best Answer

The problem was a missing dependency that wasn't on the server but was on my local machine. In our case, it was a Devart.Data.Linq dll.

To get to that answer, I turned on IIS tracing for 500 errors. That gave a little bit of information, but the really helpful thing was in the web.config setting the <system.web><customErrors mode="Off"/></system.web> This pointed to a missing dynamically-loaded dependency. After adding this dependency and telling it to be copied locally, the server started working.

Related Solutions

Using Custom Domains With IIS Express

This is what worked for me (Updated for VS 2013, see revision history for 2010, for VS 2015 see this: https://stackoverflow.com/a/32744234/218971):

Right-click your Web Application Project ▶ Properties ▶ Web, then configure the Servers section as follows:
- Select IIS Express ▼ from the drop down
- Project Url: http://localhost
- Override application root URL: http://dev.example.com
- Click Create Virtual Directory (if you get an error here you may need to disable IIS 5/6/7/8, change IIS's Default Site to anything but port :80, make sure Skype isn't using port 80, etc.)
Optionally: Set the Start URL to http://dev.example.com

Open %USERPROFILE%\My Documents\IISExpress\config\applicationhost.config (Windows XP, Vista, and 7) and edit the site definition in the <sites> config block to be along the lines of the following:

<site name="DevExample" id="997005936">
    <application path="/" applicationPool="Clr2IntegratedAppPool">
        <virtualDirectory
            path="/"
            physicalPath="C:\path\to\application\root" />
    </application>
    <bindings>
        <binding
            protocol="http"
            bindingInformation=":80:dev.example.com" />
    </bindings>
    <applicationDefaults applicationPool="Clr2IntegratedAppPool" />
</site>

If running MVC: make sure the applicationPool is set to one of the "Integrated" options (like "Clr2IntegratedAppPool").
Open your hosts file and add the line 127.0.0.1 dev.example.com.
► Start your application!

Some great advice from the comments:

You may need to run Visual Studio as Administrator.

If you want to make other devs see your IIS run netsh http add urlacl url=http://dev.example.com:80/ user=everyone

If you want the site to resolve for all hosts set bindingInformation="*:80:". Use any port you want, 80 is just convenient. To resolve all hosts you'll need to run Visual Studio as an administrator

IIS 500.19 with 0x80070005 The requested page cannot be accessed because the related configuration data for the page is invalid error

This can also happen if the site is configured to use the IIS URL Rewrite module but it is not installed.

Best Answer

Related Solutions

Using Custom Domains With IIS Express

IIS 500.19 with 0x80070005 The requested page cannot be accessed because the related configuration data for the page is invalid error

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