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 host

Answer 1

There are just so many things that could cause this error. Here are a few that worked for me:

1. Just delete the web.config in your wwwroot folder. It will get recreated correctly on compilation.
2. If you are trying to use SSL and in your IIS Express and moving your SSL Cert to the Trusted Root Certification Authorities folder didn't work. In the Debug tab of the Properties of the project you are trying to run. Try unclicking the Enable SSL checkbox and then clicking it again to enable it and get a different port. You may have to do this a few times.

Answer 2

I used RC1 and EF First Code Approach. Good idea to start investigation is to run project with option: "Start project without debbuging" (Ctrl+F5). Then I get more meaningful error for me: "The configuration section 'entityFramework' cannot be read because it is missing a section declaration." It didn't work for me because of web.config file.

Answer 3

Another potential solution
For anyone playing with SSL settings, I found just changing the SSL port in the launchSettings.json file to another nearby port solved the problem.

FYI, I couldn't find anything on the machine using the original port, nor did I get a port in use error.

Answer 4

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.

Answer 5

Assuming you are running IIS Express with SSL Enabled depending on your installation you will have to put your IIS Express Development Certificate(Issued To "localhost"/ Issued By "localhost") in either [Local Computer\Personal\Certificates] or [Local Computer\Trusted Root Certification\Certificates]. One of those should work. (Using Windows 10 + VS2015). HTH