An error occurred attempting to determine the process id of the DNX process hosting your application

Question

I get this error message when I'm trying to start the application.

An error occurred attempting to determine the process id of the DNX process hosting your application

Is there a way to fix the problem?

Answer 1

For me the problem was solved by closing down Visual Studio, deleting

project.lock.json

and starting Visual Studio again.

Edit: I was using RC1.

Answer 2

Microsoft changed the hosting model as described in the release notes.

In project.json replace the dependency

"Microsoft.AspNet.Server.IIS": "1.0.0-beta7"

with

"Microsoft.AspNet.Server.Kestrel": "1.0.0-beta8"

---

In web.config in the handlers section remove every entry except

<add name="httpPlatformHandler" path="*" verb="*" modules="httpPlatformHandler" resourceType="Unspecified" />

The complete web.config will look like this:

<?xml version="1.0" encoding="utf-8"?>
<configuration>
  <system.webServer>
    <handlers>
      <add name="httpPlatformHandler" path="*" verb="*" modules="httpPlatformHandler" resourceType="Unspecified"/>
    </handlers>
    <httpPlatform processPath="%DNX_PATH%" arguments="%DNX_ARGS%" stdoutLogEnabled="false" startupTimeLimit="3600"/>
  </system.webServer>
</configuration>

---

RC1: While using RC1 I had the error after moving the solution folder. After deleting the bin and obj folders everything worked again.
As user764754 noted, simply restarting Visual Studio can also help.

Answer 3

For other people having this problem, in cases in which the other solutions don't work - I found the answer in this thread: Forcing to use SSL: An error ocurred attempting to determine the process id of the DNX process hosting your application

I your project uses or enforces SSL run it without debugging (CTRL+F5) first, it will ask you to generate a local SSL cert, and after that debugging will work and the error will be gone.