Closing Chunk Parameters tabs with chunk selected and reopening Destructible will cause crash

When opening a DM selecting any chunk, even the unfractured mesh, closing the chunk parameters tab and reopening the DM will result in a crash.

If that DM is opened and clicked in the viewport it will still cause the crash. The only way around that is to open and click to re-add the chunk parameters tab. This will reset and prevent the crashing from happening.

1. Open UE4
2. Create or open an existing Destructible
3. Select any chunk (can even be the unfractured mesh)
4. Select and close the Chunk Parameters Tab
5. Exit the DM Editor
6. Re-Open the DM
7. Click the mesh or any chunks
8. Editor will Crash

Results: The editor will crash when the DM is opened back up after closing the Chunk Parameters tab

MachineId:621DFBAB44A9B51A4245D5A61065407D
EpicAccountId:7c6293d6bf1940c0bc89e1494c5ba9d7

Unknown exception - code 00000001 (first/second chance not available)

Assertion failed: IsValid() [Link Removed] [Line: 658]

KERNELBASE + 23544 bytes
UE4Editor_Core!FOutputDeviceWindowsError::Serialize() + 292 bytes [d:\buildfarm\buildmachine_++depot+ue4-releases+4.7\engine\source\runtime\core\private\windows\windowsplatformoutputdevices.cpp:95]
UE4Editor_Core!FOutputDevice::Logf__VA() + 248 bytes [d:\buildfarm\buildmachine_++depot+ue4-releases+4.7\engine\source\runtime\core\private\misc\outputdevice.cpp:144]
UE4Editor_Core!FDebug::AssertFailed() + 1079 bytes [d:\buildfarm\buildmachine_++depot+ue4-releases+4.7\engine\source\runtime\core\private\misc\outputdevice.cpp:224]
UE4Editor_DestructibleMeshEditor!FDestructibleMeshEditor::SetSelectedChunks() + 81 bytes [d:\buildfarm\buildmachine_++depot+ue4-releases+4.7\engine\source\editor\destructiblemesheditor\private\destructiblemesheditor.cpp:535]
UE4Editor_DestructibleMeshEditor!FDestructibleMeshEditorViewportClient::UpdateChunkSelection() + 1723 bytes [d:\buildfarm\buildmachine_++depot+ue4-releases+4.7\engine\source\editor\destructiblemesheditor\private\sdestructiblemesheditorviewport.cpp:191]
UE4Editor_DestructibleMeshEditor!FDestructibleMeshEditorViewportClient::ProcessClick() + 1776 bytes [d:\buildfarm\buildmachine_++depot+ue4-releases+4.7\engine\source\editor\destructiblemesheditor\private\sdestructiblemesheditorviewport.cpp:335]
UE4Editor_UnrealEd!FEditorViewportClient::ProcessClickInViewport() + 344 bytes [d:\buildfarm\buildmachine_++depot+ue4-releases+4.7\engine\source\editor\unrealed\private\editorviewportclient.cpp:2176]
UE4Editor_UnrealEd!FEditorViewportClient::InputKey() + 1349 bytes [d:\buildfarm\buildmachine_++depot+ue4-releases+4.7\engine\source\editor\unrealed\private\editorviewportclient.cpp:1964]
UE4Editor_Engine!FSceneViewport::OnMouseButtonUp() + 405 bytes [d:\buildfarm\buildmachine_++depot+ue4-releases+4.7\engine\source\runtime\engine\private\slate\sceneviewport.cpp:428]
UE4Editor_Slate!SViewport::OnMouseButtonUp() + 187 bytes [d:\buildfarm\buildmachine_++depot+ue4-releases+4.7\engine\source\runtime\slate\private\widgets\sviewport.cpp:156]
UE4Editor_Slate!<lambda_de96dc3471181973108233c6db1f9843>::operator()() + 188 bytes [d:\buildfarm\buildmachine_++depot+ue4-releases+4.7\engine\source\runtime\slate\private\framework\application\slateapplication.cpp:3985]
UE4Editor_Slate!FEventRouter::Route<FReply,FEventRouter::FToLeafmostPolicy,FPointerEvent,<lambda_de96dc3471181973108233c6db1f9843> >() + 215 bytes [d:\buildfarm\buildmachine_++depot+ue4-releases+4.7\engine\source\runtime\slate\private\framework\application\slateapplication.cpp:202]
UE4Editor_Slate!FSlateApplication::ProcessMouseButtonUpEvent() + 601 bytes [d:\buildfarm\buildmachine_++depot+ue4-releases+4.7\engine\source\runtime\slate\private\framework\application\slateapplication.cpp:3988]
UE4Editor_Slate!FSlateApplication::OnMouseUp() + 294 bytes [d:\buildfarm\buildmachine_++depot+ue4-releases+4.7\engine\source\runtime\slate\private\framework\application\slateapplication.cpp:3949]
UE4Editor_Core!FWindowsApplication::ProcessDeferredMessage() + 3573 bytes [d:\buildfarm\buildmachine_++depot+ue4-releases+4.7\engine\source\runtime\core\private\windows\windowsapplication.cpp:1373]
UE4Editor_Core!FWindowsApplication::DeferMessage() + 318 bytes [d:\buildfarm\buildmachine_++depot+ue4-releases+4.7\engine\source\runtime\core\private\windows\windowsapplication.cpp:1669]
UE4Editor_Core!FWindowsApplication::ProcessMessage() + 4016 bytes [d:\buildfarm\buildmachine_++depot+ue4-releases+4.7\engine\source\runtime\core\private\windows\windowsapplication.cpp:742]
UE4Editor_Core!FWindowsApplication::AppWndProc() + 114 bytes [d:\buildfarm\buildmachine_++depot+ue4-releases+4.7\engine\source\runtime\core\private\windows\windowsapplication.cpp:604]
user32 + 9268 bytes
user32 + 8855 bytes
UE4Editor_Core!FWindowsPlatformMisc::PumpMessages() + 118 bytes [d:\buildfarm\buildmachine_++depot+ue4-releases+4.7\engine\source\runtime\core\private\windows\windowsplatformmisc.cpp:774]
UE4Editor!FEngineLoop::Tick() + 3737 bytes [d:\buildfarm\buildmachine_++depot+ue4-releases+4.7\engine\source\runtime\launch\private\launchengineloop.cpp:2233]
UE4Editor!GuardedMain() + 1404 bytes [d:\buildfarm\buildmachine_++depot+ue4-releases+4.7\engine\source\runtime\launch\private\launch.cpp:142]
UE4Editor!GuardedMainWrapper() + 26 bytes [d:\buildfarm\buildmachine_++depot+ue4-releases+4.7\engine\source\runtime\launch\private\windows\launchwindows.cpp:126]
UE4Editor!WinMain() + 249 bytes [d:\buildfarm\buildmachine_++depot+ue4-releases+4.7\engine\source\runtime\launch\private\windows\launchwindows.cpp:202]
UE4Editor!__tmainCRTStartup() + 329 bytes [f:\dd\vctools\crt\crtw32\dllstuff\crtexe.c:618]