Debugging MVC application in VS2012 attempts to st

Question

UPDATE

I'm certain this is a Visual Studio bug with no obvious solution. I've encountered a number of people who have the same exact issue. I have submitted a bug ticket with Microsoft here:

http://connect.microsoft.com/VisualStudio/feedback/details/778864/vs2012-is-spawning-two-iisexpress-processes-when-attempting-to-debug

If you are having the same issue as described below, please go vote up the bug ticket so that it gets more attention.

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Whenever I attempt to debug an MVC3 (or MVC4) application in Visual Studio 2012 configured to run on IIS express (version 8), I get the following error:

Here's the kicker: IIS Express is starting, even though Visual Studio doesn't think so and the debugger fails to attach. The IIS Express tray opens and I can clearly see all configured websites are started:

Oddly enough, the IIS Express System Tray reports that there were some errors when running IIS Express. Here's what it says:

This is a serious WTF. It's reporting that 8080 is being used by an IIS Express Process - the one that was just started by Visual Studio. So, Visual Studio is attempting to launch IIS twice, and when it predictably fails the second time, the debugger bails. I should note that before launching the debug configuration in Visual Studio, I made absolutely sure no IIS Express processes were already running. I used Process Monitor to verify that Visual Studio is in fact attempting to launch IIS Express twice:

Notice in the screen shot above you can clearly see websites running on IIS Express PID 4732. PID 4924 is the second failed attempt at launching IIS Express.

This issue was initially occurring on a Windows 7 installation. I reformatted completely, installed a fresh copy of VS2012, and got the same issue. I went a step further and reformatted, installed Windows 8 and a fresh copy of VS2012, and the issue persists.

I have created brand new blank MVC3 and MVC4 projects. Nothing fixes it.

I'm tearing out my hair here. Any help would be greatly appreciated.

Answer 1

Have a look at the answer here:

http://forums.asp.net/t/1953087.aspx?VS+2013+Unable+to+launch+the+IIS+Express+Web+Server

It was strange behavior on a Windows 8 machine when 'bg' was part of the username

Answer 2

Just in case, do you have 127.0.0.1 localhost defined in folder/system32/drivers/stc/hosts ? Otherwize, you can check here, this might just be the key.

Cheers

Answer 3

I had the same issue on Windows 8 and Windows 8.1 using my domain account. In my case changing the Documents folder path (Right click on the Documents folder -> Properties -> Location) from C:\Users\username\Documents to D:\Documents helped

Answer 4

This week, I experienced this identical issue: IIS Express starts, but VS complains it couldn't start IIS Express and debugging fails.

I finally resolved the issue by applying the June 2014 hot-fix to IIS Express:

• http://www.microsoft.com/en-us/download/confirmation.aspx?id=43380

We (my IT support and I) found this hotfix after stumbling over and following a very unlikely problem. Apparently, MS verified a bug in IISExpress 8.0 which results in it misbehaving if any part of the application name contains the letter combination "bg" (my username begins with bg):

• https://connect.microsoft.com/VisualStudio/feedback/details/848945/visual-studio-2012-iis-express-fails-to-start-if-application-name-contains-bg

Note: VS 2013 Update 4 already contains this fix, which may be why some people had success simply by updating to VS 2013.

Some other links we found concerning the issue (you may have to skim a bit to find the topic):

• http://forums.asp.net/t/1953087.aspx?VS+2013+Unable+to+launch+the+IIS+Express+Web+Server
• https://connect.microsoft.com/VisualStudio/feedback/details/865116/process-with-an-id-of-id-is-not-running

Answer 5

There are two instances of the site FrontEnd running of course, but notice that one instance is HTTP and the other HTTPS.

It's possible to get two instances when SSL Enabled is set to True in the web site properties but the Project Url on the Web tab is set to an HTTP address.

Make them both HTTP (or HTTPS) and that might fix it.