App error: Object reference not set to an instance of an object.

[thomas694]

Sometimes users let the app report an error that occurred, but it's unclear which steps caused it. We have the error message, the stack trace and need to find the root cause... Any help is welcome.

ExceptionMessage: Object reference not set to an instance of an object. ExceptionType: System.NullReferenceException Callstack:

at TumblThree.Applications.Properties.QueueSettings.ReplaceAll(IEnumerable1 newBlogNames, IEnumerable1 newBlogTypes) in C:\projects\Tumblthree\src\TumblThree\TumblThree.Applications\Properties\QueueSettings.cs:line 39 at TumblThree.Applications.Controllers.ModuleController.Shutdown() in C:\projects\Tumblthree\src\TumblThree\TumblThree.Applications\Controllers\ModuleController.cs:line 193 at TumblThree.Presentation.App.DoShutdown() in C:\projects\Tumblthree\src\TumblThree\TumblThree.Presentation\App.xaml.cs:line 114 at TumblThree.Presentation.App.b__7_1() in C:\projects\Tumblthree\src\TumblThree\TumblThree.Presentation\App.xaml.cs:line 47 at System.Windows.Threading.ExceptionWrapper.InternalRealCall(Delegate callback, Object args, Int32 numArgs) at System.Windows.Threading.ExceptionWrapper.TryCatchWhen(Object source, Delegate callback, Object args, Int32 numArgs, Delegate catchHandler)

TumblThreeVersion: 2.13.0.442 (64 bit)