Hi,

I suspect that when you created the .net solution you didn't close the existing open arduino solution before hand.

This would give a solution with two projects in it. In that case you would need to right click the .net project and set it as "Startup project" so that Visual Studio would consider it the project to build.

The first project in a solution is automatically set as the startup project which would have been your arduino project.

If you don't want to make it the startup project then right click the project and click "Start new instance" to start a specific .net project.

You should also ensure that the arduino code of an arduino project is not the active code in the editor when you want to compile .net. This is configurable but won't mean much to you until you understand how vs works.

Normally you should work with single project solutions until you know visual studio a little more.

Does this make sense?

Okay sorry for assuming you were new to vs.

I'm not sure what happened either. 

Visual micro should only be active for projects that have a name the same as the containing folder and also include a .ino of the same name in the same folder. If these three rules are not hit then you should see a normal vs build, furthermore the project needs to be a c++ project.

Let me know if happens again.

Thanks