In the clients office -two of the computers running Explorer 11 are not loading up the site properly. And by that I mean the drop down navigation is not appearing. They have gone onto the original theme link and the navigation is working fine there. All the testing cross browser that I have done has shown that everything loads fine. I have asked a couple of web developer friends to have a look and they cannot find anything and I have even gone onto People Per Hour to get help but despite what people have tried - we cannot replicate the issue or fix the issue. I am going on the basis that it is purely on these two computers and there must be an issue on the clients end but I don't want to point the finger without knowing 100% for sure.
Any suggestions of what might be causing this - options for things to try or if someone has had the same issue in the past - all help would be appreciated because I do not know where to go from here.