Visual Studio exceptions not caught

First of all I will write scenario how did happen for me that visual studio did not caught exception in debug mode (debugging worked well).
One day before I updated Visual Studio 2015 from update 1 to update 2. Next day I wanted to debug an Asp.Net5 rc1 web app. And there Visual Studio should capture one exception but it did not. What happened is that it gave me that one file is not found called ExecutionTimer.cs from xunit. My first thought was that dnx does not work alright or there are some files missing in packages. I reinstalled everything (dnx amd packages) but the problem still existed. Next I tried to throw an exception and realize that Visual Studio does not break at that exception. I searched web for resolution but all that is written about it is in this window: Exception Settings -> Common Language Runtime Exceptions. Then you can select at which exceptions Visual Studio automatically breaks. I never changed something so I thought while updating Visual Studio some settings could get overridden but the same problem have my co-worker without any update. His solution was to check checkboxes in Common Language Runtime Exceptions for specific Exception types. Because there were just to many (you have to select right ones not all) I tried just to reset settings for Visual Studio. It can be done like that: Tools -> Import And Export Settings ... -> Reset all settings. That worked well for me but the only problem was I did not have old settings backup. So I suggest it is good from time to time to export current settings just in case you need to restore them in occasions like this one.