I figured it out, since I was using an interface as a marker for my events, I had to change the query from the SO question from
var types = Assembly.GetAssembly(typeof(SimpleCQRS.Event))
.GetTypes()
.Where(type => type.IsSubclassOf(typeof(SimpleCQRS.Event)));
to
var type = typeof(IEvent);
var types = Assembly.GetAssembly(typeof(IEvent))
.GetTypes()
.Where(t => type.IsAssignableFrom(t))
.Where(t => t.IsClass);