[CrashReport] UE4Editor-Slate!FSlateApplication::OnMouseUp(EMouseButtons::Type,FVector2D) [SlateApplication.cpp:5321]

Tried to choose f_med_brw_body_skmesh for the retargeting pose as mentioned at: https://docs.unrealengine.com/en-US/Resources/Showcases/MetaHumans/RetargetingAnimationsOntoMetaHumans/index.html

Happens every time I click the Import button to Modfiy the Post (following the steps at https://docs.unrealengine.com/en-US/Resources/Showcases/MetaHumans/RetargetingAnimationsOntoMetaHumans/index.html)

Assertion failed: (Index >= 0) & (Index < ArrayNum) [File:D:\Build\++UE4\Sync\Engine\Source\Runtime\Core\Public\Containers/Array.h] [Line: 674] Array index out of bounds: -1 from an array of size 150 

Assertion failed: (Index >= 0) & (Index < ArrayNum) [File:D:\Build\++UE4\Sync\Engine\Source\Runtime\Core\Public\Containers/Array.h] [Line: 674] Array index out of bounds: -1 from an array of size 68

ntdll!7ffecedd0000  + 9c6a4
KERNELBASE!7ffecc770000  + 1a34e
UE4Editor-Core!ReportCrash(_EXCEPTION_POINTERS *) [WindowsPlatformCrashContext.cpp:1574]
UE4Editor!7ff7a3340000  + 3b16f
VCRUNTIME140!7ffebc9f0000  + e3e0
ntdll!7ffecedd0000  + a197f
ntdll!7ffecedd0000  + 4b754
ntdll!7ffecedd0000  + 4b4a5
KERNELBASE!7ffecc770000  + 2d759
UE4Editor-Core!ReportAssert(wchar_t const *,int) [WindowsPlatformCrashContext.cpp:1627]
UE4Editor-Core!FWindowsErrorOutputDevice::Serialize(wchar_t const *,ELogVerbosity::Type,FName const &) [WindowsErrorOutputDevice.cpp:78]
UE4Editor-Core!FOutputDevice::LogfImpl(wchar_t const *,...) [OutputDevice.cpp:61]
UE4Editor-Core!static void AssertFailedImplV(const char *, const char *, int, const wchar_t *, char *) [AssertionMacros.cpp:104]
UE4Editor-Core!FDebug::CheckVerifyFailedImpl(char const *,char const *,int,wchar_t const *,...) [AssertionMacros.cpp:461]
UE4Editor-Persona!DispatchCheckVerify<void,<lambda_29b78ffea410620a1413688b21109f02> >(<lambda_29b78ffea410620a1413688b21109f02> &&) [AssertionMacros.h:165]
UE4Editor-Persona!SRetargetManager::ImportPose(UPoseAsset const *,FName const &) [SRetargetManager.cpp:462]
UE4Editor-Persona!SRetargetManager::OnImportPose() [SRetargetManager.cpp:421]
UE4Editor-Persona!TBaseSPMethodDelegateInstance<0,SRetargetManager,0,FReply ,FDefaultDelegateUserPolicy>::Execute() [DelegateInstancesImpl.h:290]
UE4Editor-Slate!SButton::ExecuteOnClick() [SButton.cpp:385]
UE4Editor-Slate!SButton::OnMouseButtonUp(FGeometry const &,FPointerEvent const &) [SButton.cpp:304]
UE4Editor-Slate!static class FReply FEventRouter::Route<FReply,FEventRouter::FToLeafmostPolicy,FPointerEvent,<lambda_cc5aea9e7377b04ce85c30c65ec3889b> >(class FSlateApplication *, class FEventRouter::FToLeafmostPolicy, struct FPointerEvent, const class FSlateApplication::RoutePointerUpEvent::__l8::<lambda_cc5aea9e7377b04ce85c30c65ec3889b> & const, ESlateDebuggingInputEvent) [SlateApplication.cpp:378]
UE4Editor-Slate!FSlateApplication::RoutePointerUpEvent(FWidgetPath const &,FPointerEvent const &) [SlateApplication.cpp:4815]
UE4Editor-Slate!FSlateApplication::ProcessMouseButtonUpEvent(FPointerEvent const &) [SlateApplication.cpp:5356]
UE4Editor-Slate!FSlateApplication::OnMouseUp(EMouseButtons::Type,FVector2D) [SlateApplication.cpp:5321]
UE4Editor-ApplicationCore!FWindowsApplication::ProcessDeferredMessage(FDeferredWindowsMessage const &) [WindowsApplication.cpp:2174]
UE4Editor-ApplicationCore!FWindowsApplication::DeferMessage(TSharedPtr<FWindowsWindow,0> &,HWND__ *,unsigned int,unsigned __int64,__int64,int,int,unsigned int) [WindowsApplication.cpp:2638]
UE4Editor-ApplicationCore!FWindowsApplication::ProcessMessage(HWND__ *,unsigned int,unsigned __int64,__int64) [WindowsApplication.cpp:1042]
UE4Editor-ApplicationCore!FWindowsApplication::AppWndProc(HWND__ *,unsigned int,unsigned __int64,__int64) [WindowsApplication.cpp:874]
USER32!7ffece2e0000  + e858
USER32!7ffece2e0000  + e299
UE4Editor-ApplicationCore!FWindowsPlatformApplicationMisc::PumpMessages(bool) [WindowsPlatformApplicationMisc.cpp:130]
UE4Editor!7ff7a3340000  + 8857
UE4Editor!7ff7a3340000  + 211ac
UE4Editor!7ff7a3340000  + 2128a