Using Box-created RSA key with C# SDK project

Our organization recently adopted Box to replace Windows shared folders.  The small development group I'm a part of will need to upload and download files from at least one Box share and so we are just getting started with the API.

Our group uses Visual Studio 2013 to develop in C# with a preferred target of .NET 4.0.  After exploring the SDK library it appears we should be able to leverage version 2.12.1 with our existing platform.

I have created an application and used the Box configuration option to generate a Public/Private keypair.

Where I'm getting hung up is when I try to use the keypair with the Box.V2.Samples.JWTAuth project.  I copied the privateKey out of the JSON file, replaced the \n's with actual carriage returns, and pasted it into the private_key.pem file:

I placed the other values in app.config and started the console app, which produces this error:

Clearly there's something about the formatting of the key that BouncyCastle doesn't like.  

What do I need to do to make the key acceptable?