Crash after Clearing Sound Wave Asset and Deleting Media Player from Content Browser

A crash occurs when deleting a Media Player asset from the Content Browser that contained a previously referenced Sound Wave asset.

This issue does not occur in any past engine versions as the preview release contained the newly added Media Framework.

1. Create a new blank blueprint project in 4.13 preview 1
2. Import the attached media source file.
3. Add a Media Player via the Content browser dropdown menu.
4. Check the 'Audio Output SoundWave Asset'
5. Open the Media Player and play the video at least once.
6. Clear out the Sound Wave field within the 'Ouput' section.
7. Close the Media Player.
8. Delete the Media Player from the Content Browser.

Outcome Crash occurs

Expected No crash occurs and the associate Media Player is deleted successfully.

UE4Editor_WmfMedia!FWmfMediaTracks::SetAudioSink()
UE4Editor_MediaAssets!UMediaPlayer::BeginDestroy() mediaplayer.cpp:453
UE4Editor_CoreUObject!UObject::ConditionalBeginDestroy() obj.cpp:739
UE4Editor_CoreUObject!CollectGarbageInternal() garbagecollection.cpp:1281
UE4Editor_CoreUObject!CollectGarbage() garbagecollection.cpp:1320
UE4Editor_UnrealEd!PackageTools::UnloadPackages() packagetools.cpp:325
UE4Editor_UnrealEd!ObjectTools::CleanupAfterSuccessfulDelete() objecttools.cpp:1493
UE4Editor_UnrealEd!ObjectTools::DeleteObjectsUnchecked() objecttools.cpp:1823
UE4Editor_UnrealEd!FAssetDeleteModel::DoDelete() assetdeletemodel.cpp:260
UE4Editor_UnrealEd!SDeleteAssetsDialog::Delete() sdeleteassetsdialog.cpp:683
UE4Editor_UnrealEd!TMemberFunctionCaller<SDeleteAssetsDialog,FReply() delegateinstanceinterface.h:161
UE4Editor_UnrealEd!TTupleImpl<TIntegerSequence<unsigned int> >::ApplyAfter<TMemberFunctionCaller<SDeleteAssetsDialog,FReply() tuple.h:115
UE4Editor_UnrealEd!TBaseSPMethodDelegateInstance<0,SDeleteAssetsDialog,0,FReply __cdecl() delegateinstancesimpl.h:317
UE4Editor_Slate!TBaseDelegate<FReply>::Execute() delegatesignatureimpl.inl:521
UE4Editor_Slate!SButton::OnMouseButtonUp() sbutton.cpp:278
UE4Editor_Slate!<lambda_8d0e9a1da76abd0a756a3a9d775f5ed1>::operator() slateapplication.cpp:4891
UE4Editor_Slate!FEventRouter::Route<FReply,FEventRouter::FToLeafmostPolicy,FPointerEvent,<lambda_8d0e9a1da76abd0a756a3a9d775f5ed1> >() slateapplication.cpp:215
UE4Editor_Slate!FSlateApplication::RoutePointerUpEvent() slateapplication.cpp:4880
UE4Editor_Slate!FSlateApplication::ProcessMouseButtonUpEvent() slateapplication.cpp:5338
UE4Editor_Slate!FSlateApplication::OnMouseUp() slateapplication.cpp:5318
UE4Editor_Core!FWindowsApplication::ProcessDeferredMessage() windowsapplication.cpp:1584
UE4Editor_Core!FWindowsApplication::DeferMessage() windowsapplication.cpp:1930
UE4Editor_Core!FWindowsApplication::ProcessMessage() windowsapplication.cpp:747
UE4Editor_Core!FWindowsApplication::AppWndProc() windowsapplication.cpp:669
user32!<Unknown>
user32!<Unknown>
UE4Editor_Core!FWindowsApplication::PumpMessages() windowsapplication.cpp:1942
UE4Editor_Slate!FSlateApplication::TickPlatform() slateapplication.cpp:1481
UE4Editor_Slate!FSlateApplication::AddModalWindow() slateapplication.cpp:1978
UE4Editor_UnrealEd!UEditorEngine::EditorAddModalWindow() editorengine.cpp:3588
UE4Editor_UnrealEd!ObjectTools::DeleteObjects() objecttools.cpp:1698
UE4Editor_UnrealEd!ObjectTools::DeleteAssets() objecttools.cpp:1605
UE4Editor_ContentBrowser!FAssetContextMenu::ExecuteDelete() assetcontextmenu.cpp:1784
UE4Editor_ContentBrowser!SContentBrowser::HandleDeleteCommandExecute() scontentbrowser.cpp:1972
UE4Editor_ContentBrowser!TBaseSPMethodDelegateInstance<0,SContentBrowser,0,TTypeWrapper<void> __cdecl() delegateinstancesimpl.h:317
UE4Editor_ContentBrowser!TBaseSPMethodDelegateInstance<0,SContentBrowser,0,void __cdecl() delegateinstancesimpl.h:423
UE4Editor_Slate!FUICommandList::ConditionalProcessCommandBindings() uicommandlist.cpp:211
UE4Editor_Slate!FUICommandList::ProcessCommandBindings() uicommandlist.cpp:155
UE4Editor_ContentBrowser!SContentBrowser::OnKeyDown() scontentbrowser.cpp:971
UE4Editor_Slate!<lambda_2afcd964c763e269e2d1a63f3a72f846>::operator() slateapplication.cpp:4507
UE4Editor_Slate!FEventRouter::Route<FReply,FEventRouter::FBubblePolicy,FKeyEvent,<lambda_2afcd964c763e269e2d1a63f3a72f846> >() slateapplication.cpp:215
UE4Editor_Slate!FEventRouter::RouteAlongFocusPath<FEventRouter::FBubblePolicy,<lambda_2afcd964c763e269e2d1a63f3a72f846>,FKeyEvent>() slateapplication.cpp:197
UE4Editor_Slate!FSlateApplication::ProcessKeyDownEvent() slateapplication.cpp:4505
UE4Editor_Slate!FSlateApplication::OnKeyDown() slateapplication.cpp:4420
UE4Editor_Core!FWindowsApplication::ProcessDeferredMessage() windowsapplication.cpp:1419
UE4Editor_Core!FWindowsApplication::DeferMessage() windowsapplication.cpp:1930
UE4Editor_Core!FWindowsApplication::ProcessMessage() windowsapplication.cpp:747
UE4Editor_Core!FWindowsApplication::AppWndProc() windowsapplication.cpp:669
user32!<Unknown>
user32!<Unknown>
UE4Editor_Core!FWindowsPlatformMisc::PumpMessages() windowsplatformmisc.cpp:905
UE4Editor!FEngineLoop::Tick() launchengineloop.cpp:2788
UE4Editor!GuardedMain() launch.cpp:156
UE4Editor!GuardedMainWrapper() launchwindows.cpp:126
UE4Editor!WinMain() launchwindows.cpp:202
UE4Editor!__scrt_common_main_seh() exe_common.inl:264
kernel32!<Unknown>
ntdll!<Unknown>