ASP.NET MVC 4 - Cannot perform runtime binding on a null reference

OK I am posting the full answer here -

1. Try @ before if(@ViewBag.Stats[index] == null){ and remove @ from @ViewBag inside the if so that it look like this - @if(ViewBag.Stats[index] == null){

2. You are setting index = 0, inside foreach, so it is initialised in every loop. Initialise it outside foreach like this

   var index = 0; foreach ...

if you are facing problem for the scope try this -

@{
    var index = 0;
    foreach (....) {
        .......
        index++
    }
}