Fireware update Exception

My DK2 was working fine for ages and stopped working and looking through loads of post I still cant resolve it.

Although my firmware is up to date I just went to update it anyway.

In the following zip file there is the exception file and the mini dump
https://dl.dropboxusercontent.com/u/17711594/oculus/Exception%20Report%20%282014-12-20%2015.51.37%29.zip