UMG Drag Widget Bug?

This bug was introduced in 4.11 but is present in all version after as well, I also tested this on 4.10.4 and this bug isn’t present.

Its going to be a hard bug to filter out but it will be easier showing a video of the bug.

VIDEO SHOWING BUG

There are no errors when this happens but i can produce a engine crash when using a loot filter in my project when this UMG bug is in affect it may help or not?

Assertion failed: IsValid() [File:D:\Build\++UE4+Release-4.12+Compile\Sync\Engine\Source\Runtime\Core\Public\Templates\SharedPointer.h] [Line: 739] 



UE4Editor_Core!FDebug::AssertFailed() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\core\private\misc\outputdevice.cpp:440]
UE4Editor_UMG!UComboBoxString::HandleSelectionChanged() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\umg\private\components\comboboxstring.cpp:218]
UE4Editor_UMG!TBaseUObjectMethodDelegateInstance<0,UComboBoxString,TTypeWrapper<void> __cdecl(TSharedPtr<FString,0>,enum ESelectInfo::Type)>::Execute() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\core\public\delegates\delegateinstancesimpl_variadics.inl:760]
UE4Editor_UMG!TBaseUObjectMethodDelegateInstance<0,UComboBoxString,void __cdecl(TSharedPtr<FString,0>,enum ESelectInfo::Type)>::ExecuteIfSafe() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\core\public\delegates\delegateinstancesimpl_variadics.inl:850]
UE4Editor_UMG!TBaseDelegate<void,TSharedPtr<FString,0>,enum ESelectInfo::Type>::ExecuteIfBound() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\core\public\delegates\delegatesignatureimpl_variadics.inl:608]
UE4Editor_UMG!SComboBox<TSharedPtr<FString,0> >::OnSelectionChanged_Internal() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\slate\public\widgets\input\scombobox.h:325]
UE4Editor_UMG!TBaseSPMethodDelegateInstance<0,SComboBox<TSharedPtr<FString,0> >,0,TTypeWrapper<void> __cdecl(TSharedPtr<FString,0>,enum ESelectInfo::Type)>::Execute() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\core\public\delegates\delegateinstancesimpl_variadics.inl:321]
UE4Editor_UMG!TBaseSPMethodDelegateInstance<0,SComboBox<TSharedPtr<FString,0> >,0,void __cdecl(TSharedPtr<FString,0>,enum ESelectInfo::Type)>::ExecuteIfSafe() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\core\public\delegates\delegateinstancesimpl_variadics.inl:428]
UE4Editor_UMG!TBaseDelegate<void,TSharedPtr<FString,0>,enum ESelectInfo::Type>::ExecuteIfBound() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\core\public\delegates\delegatesignatureimpl_variadics.inl:608]
UE4Editor_UMG!SListView<TSharedPtr<FString,0> >::Private_SignalSelectionChanged() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\slate\public\widgets\views\slistview.h:618]
UE4Editor_UMG!STableRow<TSharedPtr<FString,0> >::OnMouseButtonUp() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\slate\public\widgets\views\stablerow.h:449]
UE4Editor_Slate!<lambda_8d0e9a1da76abd0a756a3a9d775f5ed1>::operator()() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\slate\private\framework\application\slateapplication.cpp:4598]
UE4Editor_Slate!FEventRouter::Route<FReply,FEventRouter::FToLeafmostPolicy,FPointerEvent,<lambda_8d0e9a1da76abd0a756a3a9d775f5ed1> >() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\slate\private\framework\application\slateapplication.cpp:215]
UE4Editor_Slate!FSlateApplication::RoutePointerUpEvent() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\slate\private\framework\application\slateapplication.cpp:4587]
UE4Editor_Slate!FSlateApplication::ProcessMouseButtonUpEvent() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\slate\private\framework\application\slateapplication.cpp:5041]
UE4Editor_Slate!FSlateApplication::OnMouseUp() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\slate\private\framework\application\slateapplication.cpp:5021]
UE4Editor_Core!FWindowsApplication::ProcessDeferredMessage() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\core\private\windows\windowsapplication.cpp:1510]
UE4Editor_Core!FWindowsApplication::DeferMessage() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\core\private\windows\windowsapplication.cpp:1850]
UE4Editor_Core!FWindowsApplication::ProcessMessage() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\core\private\windows\windowsapplication.cpp:745]
UE4Editor_Core!FWindowsApplication::AppWndProc() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\core\private\windows\windowsapplication.cpp:667]
user32
user32
UE4Editor_Core!FWindowsPlatformMisc::PumpMessages() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\core\private\windows\windowsplatformmisc.cpp:903]
UE4Editor!FEngineLoop::Tick() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\launch\private\launchengineloop.cpp:2729]
UE4Editor!GuardedMain() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\launch\private\launch.cpp:148]
UE4Editor!GuardedMainWrapper() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\launch\private\windows\launchwindows.cpp:126]
UE4Editor!WinMain() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\launch\private\windows\launchwindows.cpp:200]
UE4Editor!__scrt_common_main_seh() [f:\dd\vctools\crt\vcstartup\src\startup\exe_common.inl:264]
kernel32
ntdll

link text

Can one of the devs please take a look.

Hello OverRated_AU,

I have a few questions for you that will help narrow down what issue it is that you are experiencing.

Quick questions:

  1. Can you reproduce this issue in a clean project?
  2. If so, could you provide a detailed list of steps to reproduce this issue on our end?
  3. Could you provide screen shots of any widgets/blueprints that may be involved?
  4. If you open a copy instead of convert in place, does this make a difference?
  5. Could you also try removing your saved and intermediate files before upgrading the project?

Note you may want to make a back up of any files removed.

Hi Rudy,

I will create a new project and see if i can reproduce the issue for you, I have tried opening it without converting it and opening it as a copy both result with the same issue, I have also tried removing the saved and intermediate files before updating as well which didn’t help.

I will report back once i have been able to recreate the logic used thanks.

Hello OverRated_AU,

Hello We have not heard back from you in a few days, so we are marking this post as Resolved for tracking purposes. If you are still experiencing the issue you reported, please respond to this message with additional information and we will follow up.

Thanks,

Hi Rudy,

Yes I’m still experiencing this issue, I haven’t had time to reproduce it as its tired into a lot of other logic to do with the inventory, the only way i can think of reproducing it would be to create a inventory system that uses the same logic, I haven’t had the time to sit down and test other methods.

Thanks.

While the video is helpful, could you elaborate on what exactly the issue is and how it is at an inverse to what you are seeing?

Sorry Rudy ill try my best to explain the issue, in the 2nd half of the video when the projects been converted to 4.12, once the widgets been dragged and drooped the grid panel fails to update its slots, i have logged where the info gets sent from the component though a UMG reference and the data is beening sent, i logged the widgets slots and the info is making it to the widget but fails to display and update, sorry if i get time on the weekend ill try to reproduce it.

Thanks

Hello OverRated_AU,

After doing a bit more digging I found that this appears to be a known issue. I have provided a link to the public tracker. Please feel free to visit this link for future updates.

Link: Unreal Engine Issues and Bug Tracker (UE-31777)

Make it a great day

Thanks Rudy that does look like the problem I’m having but what i do find strange is the name on the widget still updates fine.

One guy states it works fine in 4.11 but i have tested this problem in that version and it still has the issue.