I have a couple of computers I work between for the samples I use on this blog and when switching to between of them I got the following error last week.
The project doesn’t know how to run the profile IIS Express.
I verified the project would still run on the other computer with no issues. I also verified that on the computer with the issues the project would still work using dotnet run from the command line still worked.
Next, I went to verify the project properties. Here I noticed a strange thing on the computer with the error the Debug tab of the project properties was missing a lot of setting. The following is a screen shot of the computer with the issues.
And here is the same tab on the same project, but from a different computer.
After more time that I would like to admit I was able to track down the issue. On the computer with the issue, I often work on projects that are very large which tend to slow down Visual Studio pretty bad. In an effort to speed things up a bit I when through and disabled all the extensions that I could including the Microsoft Azure App Service Tools. Turns out that disabling the previous extension caused the Microsft ASP.NET and Web Tools extension to be disabled as well (with no warning).
The only way I was able to get the project to work properly was to enable both the Microsft ASP.NET and Web Tools extension AND the Microsoft Azure App Service Tools extension. I am not sure why the Microsft ASP.NET and Web Tools extension need the Microsoft Azure App Service Tools extension but based on my experience they are related in some way.