Why does Visual Studio 2015 console runner not recognize MSpecs?

I've written some MSpecs, but Visual Studio (2015) test runner does not recognize them. I've added the Machine.Specifications.Runner.Console and all required Machine.Specification-packages using the NuGet-PM. But when I choose Test->Run Test, the mspec-containing file is not even listed. Beyond is an example of the mspecs I wrote so far, which is located in an own project/solution that contains some other (regular unit) test, which all run fine btw.

[Subject(typeOf(ControllerForm)]
public class When_file_with_multiple_procedures_is_opened:ControllerFormSpecs
{
   static ControllerForm subject;
   ...
   Establish context =()=>
   {
       subject = new ControllerForm(...);
       path="someRandomPath";
   };

   Because of =()=>
   {
       subject.OpenFile(path);
   }

   It should_have_event =()=> subject.eventExist.ShouldBeTrue();

   It should_not_have_data  =()=> subject.currentNode.ShouldBeNull();

   Cleanup after =()=>
   {
       subject = null;
   };
 }

What am I missing?

Note: Using ReSharper is not an option here. I know many people like it and even more recommend it, but my company allready declined my request for that.

edit: Using the 'Machine.Specifications.Console.Runner' you got to keep the following in mind:

1) Change the working directory of the console to the very one, where all mespc.exe files are stored (in my case: c:\projects\...\Source\packages\Machine.Specifications.Runner.Console.versionnumber\tools)

2) Choose the right .exe-file depending on your debug-options (in my case: mspec-x86.exe)

3) as parameter you now have to insert the relative path to the .dll of the very project that contains the mspecs. ( again as example for my case: ..\..\..\PluginTests\bin\x86\Debug\PluginTests.dll

The console runner is for running specs from the command line. You need the Visual Studio MSTest runner installed.