Unable to start process dotnet.exe
I was having the same problem. I look for dotnet.exe in that directory and it exists but debugger cannot execute it, so i Restart Visual Studio 2015 as administrator and it works!
Just close VS delete the project.lock.json file, open VS the file will be restored and you shouldn't have problems anymore.
The issue in my case was
1- I upgrade (ported) my project (console/website) from .net 4.5 framework to donetcoreapp 2.0
2- .NET Framework 4.5 project had Web.Config
3- dotnetcore 2.0 does not have concept of maintaining web.config.
4- So whenever I ran the project I got the same error
solution:
Just deleted 'Web.Config' and it started working for me.