Why is platform dependent code not working

#if !UNITY_EDITOR
using Microsoft.AspNet.SignalR.Client;
#endif

When I run my project in the editor it works fine.
But when I want to build my project I am being told:

Error building Player because scripts
had compiler errors.

But I am not shown where.
When I comment the code above out everything works fine and I can build my project whithout any trouble. Is there any way to solve this? Right now I have to comment code out every time I have a new version just to have it back to normal in the build version.
Thanks for your help!

Since this usins statement is only active when you’re not in the editor (which mean it is only used when you build your game) and you don’t seem to require that namespace anywhere you can completely remove the line.

If for some reason you do need it (maybe for some framework that you don’t use yet) you should check that you have the actual assembly as well as all dependencies in your project. However if you have no idea for what you need it and the project build fine without it i doubt you actually require it. Inside which file / script is that code fragment located?

Do builds complete? You’re going to have to debug from a build rather than in the editor. Make sure you build a development build.