Error pops up, but big box works fine after. Windows 10 Home 64 Bit.

[Polocatfan]

The given key was not present in the dictionary.

App:     Big Box
Version: 7.9-beta-3
Type:    System.Collections.Generic.KeyNotFoundException
Site:    TValue get_Item(TKey)
Source:  mscorlib

   at System.Collections.Concurrent.ConcurrentDictionary`2.get_Item(TKey key)
   at (PlatformFiltersViewModelBase )
   at Unbroken.LaunchBox.Wpf.BigBox.ViewModels.PlatformFiltersViewModelBase.OnEnter()
   at (MainViewModel )
   at Unbroken.LaunchBox.Wpf.BigBox.ViewModels.MainViewModel.OnEnter()
   at (MainViewModel , KeyEventArgs )
   at Unbroken.LaunchBox.Wpf.BigBox.ViewModels.MainViewModel.HandleKeyDown(KeyEventArgs e)
   at (MainView , Object , KeyEventArgs )
   at Unbroken.LaunchBox.Wpf.BigBox.Views.MainView.MainView_OnPreviewKeyDown(Object sender, KeyEventArgs e)
   at System.Windows.RoutedEventArgs.InvokeHandler(Delegate handler, Object target)
   at System.Windows.RoutedEventHandlerInfo.InvokeHandler(Object target, RoutedEventArgs routedEventArgs)
   at System.Windows.EventRoute.InvokeHandlersImpl(Object source, RoutedEventArgs args, Boolean reRaised)
   at System.Windows.UIElement.RaiseEventImpl(DependencyObject sender, RoutedEventArgs args)
   at System.Windows.UIElement.RaiseTrustedEvent(RoutedEventArgs args)
   at System.Windows.Input.InputManager.ProcessStagingArea()
   at System.Windows.Input.InputManager.ProcessInput(InputEventArgs input)
   at System.Windows.Input.InputProviderSite.ReportInput(InputReport inputReport)
   at System.Windows.Interop.HwndKeyboardInputProvider.ReportInput(IntPtr hwnd, InputMode mode, Int32 timestamp, RawKeyboardActions actions, Int32 scanCode, Boolean isExtendedKey, Boolean isSystemKey, Int32 virtualKey)
   at System.Windows.Interop.HwndKeyboardInputProvider.ProcessKeyAction(MSG& msg, Boolean& handled)
   at System.Windows.Interop.HwndSource.CriticalTranslateAccelerator(MSG& msg, ModifierKeys modifiers)
   at System.Windows.Interop.HwndSource.OnPreprocessMessage(Object param)
   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)

Recent Log:

   12:55:28 PM VlcMediaPlayer.Dispose(bool disposing) HandleManager.Remove
   12:55:28 PM VlcMediaPlayer.Dispose(bool disposing) EventManager.Detach
   12:55:28 PM VlcMediaPlayer.Dispose(bool disposing) Free
   12:55:28 PM VlcMediaPlayer.Dispose(bool disposing) ReleaseMediaPlayerFunction
   12:55:28 PM Music.StopAndResumeBackground Start
   12:55:30 PM Music.StopAndResumeBackground Start
   12:55:31 PM VlcMediaPlayer.Dispose(bool disposing) HandleManager.Remove
   12:55:31 PM VlcMediaPlayer.Dispose(bool disposing) EventManager.Detach
   12:55:31 PM VlcMediaPlayer.Dispose(bool disposing) Free
   12:55:31 PM VlcMediaPlayer.Dispose(bool disposing) ReleaseMediaPlayerFunction
   12:55:31 PM Music.StopAndResumeBackground Start
   12:55:31 PM VlcMediaPlayer.Dispose(bool disposing) HandleManager.Remove
   12:55:31 PM VlcMediaPlayer.Dispose(bool disposing) EventManager.Detach
   12:55:31 PM VlcMediaPlayer.Dispose(bool disposing) Free
   12:55:31 PM VlcMediaPlayer.Dispose(bool disposing) ReleaseMediaPlayerFunction
   12:55:33 PM VlcMediaPlayer.Dispose(bool disposing) HandleManager.Remove
   12:55:33 PM VlcMediaPlayer.Dispose(bool disposing) EventManager.Detach
   12:55:33 PM VlcMediaPlayer.Dispose(bool disposing) Free
   12:55:33 PM VlcMediaPlayer.Dispose(bool disposing) ReleaseMediaPlayerFunction
   12:55:36 PM VlcMediaPlayer.Dispose(bool disposing) HandleManager.Remove
   12:55:36 PM VlcMediaPlayer.Dispose(bool disposing) EventManager.Detach
   12:55:36 PM VlcMediaPlayer.Dispose(bool disposing) Free
   12:55:36 PM VlcMediaPlayer.Dispose(bool disposing) ReleaseMediaPlayerFunction
   12:55:41 PM Music.StopAndResumeBackground Start
   12:55:44 PM Music.StopAndResumeBackground Start
   12:56:32 PM Music.Pause Start
   12:56:34 PM Music.Resume Start
   12:56:34 PM Music.Pause Start
   12:56:52 PM Music.Resume Start
   12:57:20 PM Music.StopAndResumeBackground Start
   12:57:21 PM VlcMediaPlayer.Dispose(bool disposing) HandleManager.Remove
   12:57:21 PM VlcMediaPlayer.Dispose(bool disposing) EventManager.Detach
   12:57:21 PM VlcMediaPlayer.Dispose(bool disposing) Free
   12:57:21 PM VlcMediaPlayer.Dispose(bool disposing) ReleaseMediaPlayerFunction
   12:57:22 PM VlcMediaPlayer.Dispose(bool disposing) HandleManager.Remove
   12:57:22 PM VlcMediaPlayer.Dispose(bool disposing) EventManager.Detach
   12:57:22 PM VlcMediaPlayer.Dispose(bool disposing) Free
   12:57:22 PM VlcMediaPlayer.Dispose(bool disposing) ReleaseMediaPlayerFunction
   12:57:22 PM Music.StopAndResumeBackground Start
   12:57:32 PM Music.StopAndResumeBackground Start
   12:57:38 PM VlcMediaPlayer.Dispose(bool disposing) HandleManager.Remove
   12:57:38 PM VlcMediaPlayer.Dispose(bool disposing) EventManager.Detach
   12:57:38 PM VlcMediaPlayer.Dispose(bool disposing) Free
   12:57:38 PM VlcMediaPlayer.Dispose(bool disposing) ReleaseMediaPlayerFunction
   12:57:38 PM Music.StopAndResumeBackground Start
   12:57:38 PM Exception

Big Box even seems to run a bit better after the error, so I dunno.