Since last Friday (04/01/2016) we are using sonarqube in our company. Somehow one of our project\'s issues got all closed (without actually being fixed). And now the project
Thanks to @fluf we found out that the install of visual studio 2015 update 2 caused these problems.
What the root issue is here is still unkown, but its working now.
Workaround: Remove the update 2 installation of visual studio 2015 and replace it with either the update 1 or the one without the updates. Both work well enough to preform the builds en generate the code coverage files in TFS.