HttpContext.Current.Session is null

Had a funny one with an ASP.NET 4.0 C# project I am working on. I moved my session handling into a class to keep things tidy. I started getting the old reference to a null object error when trying to access a session variable.

This initially confused me a little as I was already doing an if (context.Session["myvar"] == null) on it. I then realised that it was the Session object itself that was null. I did a lot of hunting around on Google - and there are hundreds of responses (HttpContext.Current.Session is null). None of them were working for me.

I had checked that sessions were enabled and that the Session_Start event was firing in Global.asax.cs. The most useful article I came across was this one on stackoverflow.

My session handling class was using private static HttpContext context = HttpContext.Current; so that I had a shorthand to the Session object (context.Session). I swapped out the shorthand to use the full path to it (HttpContext.Current.Session) and we were off - all working!