I created a new ASP.NET 5 preview project in VS 2015 RTM (fully updated). When I try to debug it, it fails with the following exception:
The current runtime target framework is not compatible with 'ProjectName'.
Current runtime Target Framework: 'DNX,Version=v4.5 (dnx45)' Type: CLR Architecture: x86 Version: 1.0.0-beta6-12256
Please make sure the runtime matches a framework specified in project.json
I went with the default settings in the new project dialog, which I believe included a dependency on .NET 4.5.1 (though there's no mention of that dependency in the project.json file - contrary to what the exception message claims). I tried the solution offered here (defining the DNX_IIS_RUNTIME_FRAMEWORK environment variable in the project's debug settings) without success.