Select2 not working inside bootstrap modal

I am trying to use `select2` inside bootstrap modal but it is not getting the focus automatically as well as down and up arrows are not working for the populated list. The same select2 works when I put it outside the modal popup. When I searched, I found many are facing this same problem and found this post Select2 doesn't work when embedded in a bootstrap modal I implemented both the solutions from it - Removed `tabindex` from modal popup. - Commented code of `enforceFocus` function in modal.js file. But it is still not working! Any idea what I could still be missing? Edit1 It works on `firefox` when `tabindex` is removed from the modal div but not with `IE9` Edit2 I found that removing `tabindex` is actually not getting recognized by `IE9` because I can still hide the popup by escape key in IE but not in Firefox.