Komyg Komyg - 23 days ago 29
C# Question

Unable to Launch IIS Express Web Server - VS 2015 Community

I am developing a web project and I am not being able to test it using the IIS Express from the Visual Studio 2015.

I have googled this error and I found many references to it on the internet, but I believe that my case is different, because there is no other error message displayed besides "Unable to Launch IIS Express Web Server".

I've looked at the Windows Event Viewer and I got these errors below:

The worker process failed to initialize correctly and therefore could not be started. The data is the error.

The Module DLL C:\Program Files (x86)\IIS Express\aspnetcore.dll failed to load. The data is the error.

I also tried to launch the IIS Express directly using:
c:\Program Files (x86)\IIS Express>iisexpress.exe /trace:error
and I was successfull, so I think that the problem must be somewhere within Visual Studio and that my port (8080) is free.

Does anyone knows what else I can do?


If you are working with .NET core/ASP.NET core application then please make sure you have installed these-

  • .NET Core SDK

  • VS 2015 Tooling Preview 2

If it is appeared to be solution-specific then-

  • Look for applicationhost.config file at <solution-name>\.vs\config\applicationhost.config location

  • Try removing this file and run solution again.

See if this helps.