Ran across a weird exception when calling
System.Diagnostics.Process.Start( "http://www.someplace.com" );

Exception message:
The requested section was not present in the activation context

Apparently, the thread trying to start the browser must be marked STAThread.

Simply added [STAThread] attribute to the main() function, and all worked fine.

Google Groups : microsoft.public.dotnet.languages.csharp

Well, the next search result explains it more fully. Apparently, using the ProcessStartInfo parameter version of Process.Start to avoid having to set the thread apartment state.

MSDN Help on Process.Start talks about the need to set STAThread when using ProcessStartInfo.UseShellExecute set to true, or when passing a path to Process.Start()

I'm a bit confused, cuz it crashes for me when I don't have STAThread on main(), and pass a url string...but then it works by setting ProcessStartInfo.UseShellExecute to true.