LIVE: The editor crashes on Mac when attempting to open the attached Media Player .uasset

<unknown module>! FOutputDeviceMacError::HandleError() 
<unknown module>! EngineCrashHandler(FGenericCrashContext const&) 
<unknown module>! PlatformCrashHandler(int, __siginfo*, void*) 
<unknown module>! _sigtramp() 
<unknown module>! GFNameDebuggerVisualizersIsUE3() 
<unknown module>! UMediaPlayer::IsStopped() 
<unknown module>! SMediaPlayerEditorViewer::HandleOverlayStateText() 
<unknown module>! TBaseSPMethodDelegateInstance_RetVal_NoParams_Const<SMediaPlayerEditorViewer, FText, (ESPMode::Type) 
<unknown module>! FTextBlockLayout::ComputeDesiredSize(FTextBlockLayout::FWidgetArgs const&, FTextBlockStyle const&) 
<unknown module>! STextBlock::ComputeDesiredSize() 
<unknown module>! SWidget::CacheDesiredSize() 
<unknown module>! SWidget::SlatePrepass() 
<unknown module>! SWidget::SlatePrepass() 
<unknown module>! SWidget::SlatePrepass() 
<unknown module>! SWidget::SlatePrepass() 
<unknown module>! SWidget::SlatePrepass() 
<unknown module>! SWidget::SlatePrepass() 
<unknown module>! SWidget::SlatePrepass() 
<unknown module>! SWidget::SlatePrepass() 
<unknown module>! SWidget::SlatePrepass() 
<unknown module>! SWidget::SlatePrepass() 
<unknown module>! SWidget::SlatePrepass() 
<unknown module>! SWidget::SlatePrepass() 
<unknown module>! SWidget::SlatePrepass() 
<unknown module>! SWidget::SlatePrepass() 
<unknown module>! SWidget::SlatePrepass() 
<unknown module>! SWidget::SlatePrepass() 
<unknown module>! SWidget::SlatePrepass() 
<unknown module>! SWidget::SlatePrepass() 
<unknown module>! SWidget::SlatePrepass() 
<unknown module>! SWidget::SlatePrepass() 
<unknown module>! SWidget::SlatePrepass() 
<unknown module>! SWidget::SlatePrepass() 
<unknown module>! SWidget::SlatePrepass() 
<unknown module>! SWidget::SlatePrepass() 
<unknown module>! SWidget::SlatePrepass() 
<unknown module>! SWidget::SlatePrepass() 
<unknown module>! FSlateApplication::TickWindowAndChildren(TSharedRef<SWindow, (ESPMode::Type) 
<unknown module>! FSlateApplication::Tick() 
<unknown module>! FEngineLoop::Tick() 
<unknown module>! GuardedMain(wchar_t const*) 
<unknown module>! -[UE4AppDelegate() 
<unknown module>! -[FCocoaGameThread() 
<unknown module>! __NSThread__main__() 
<unknown module>! _pthread_body() 
<unknown module>! _pthread_body() 
<unknown module>! thread_start()