Search in
Sort by:

Question Status:

Search help

  • Simple searches use one or more words. Separate the words with spaces (cat dog) to search cat,dog or both. Separate the words with plus signs (cat +dog) to search for items that may contain cat but must contain dog.
  • You can further refine your search on the search results page, where you can search by keywords, author, topic. These can be combined with each other. Examples
    • cat dog --matches anything with cat,dog or both
    • cat +dog --searches for cat +dog where dog is a mandatory term
    • cat -dog -- searches for cat excluding any result containing dog
    • [cats] —will restrict your search to results with topic named "cats"
    • [cats] [dogs] —will restrict your search to results with both topics, "cats", and "dogs"

[BUG] Create UserWidget Widget crashes Editor when PIE

I created a project based on the Blueprint First Person template.

I was experimenting with UMG Widgets, and wanted to not have any widgets added to screen but not remove my Blueprint nodes to create a Widget. I did this by setting the Class variable in a Create UserWidget Widget node to "User Widget". When this is set, the Editor crashes when trying to Play In Editor.

I believe the key portion of the error message in the Crash Reporter is: "Class which was marked abstract was trying to be loaded. It will be null"

This error is repeatable. It will crash the Editor everytime you Play, or Simulate.

This is the callstack from the crash reporter:

Access violation - code c0000005 (first/second chance not available)

Ensure condition failed: false [File:D:\BuildFarm\buildmachine_++depot+UE4-Releases+4.6\Engine\Source\Runtime\CoreUObject\Private\UObject\UObjectGlobals.cpp] [Line: 1597] Class which was marked abstract was trying to be loaded. It will be null

UE4Editor_UMG + 658745 bytes UE4Editor_UMG + 90249 bytes UE4Editor_UMG + 503384 bytes UE4Editor_UMG + 1533434 bytes UE4Editor_CoreUObject + 563956 bytes UE4Editor_CoreUObject + 1348671 bytes UE4Editor_CoreUObject + 1471421 bytes UE4Editor_CoreUObject + 1615878 bytes UE4Editor_CoreUObject + 1477214 bytes UE4Editor_CoreUObject + 1350042 bytes UE4Editor_CoreUObject + 1621364 bytes UE4Editor_CoreUObject + 1477214 bytes UE4Editor_CoreUObject + 563956 bytes UE4Editor_CoreUObject + 1475014 bytes UE4Editor_Engine + 1640529 bytes UE4Editor_Engine + 9918747 bytes UE4Editor_Engine + 3683489 bytes UE4Editor_Engine + 3792845 bytes UE4Editor_Engine + 3803171 bytes UE4Editor_Engine + 3805342 bytes UE4Editor_UnrealEd + 4271756 bytes UE4Editor_UnrealEd + 4561611 bytes UE4Editor_UnrealEd + 4660963 bytes UE4Editor_UnrealEd + 1801811 bytes UE4Editor_UnrealEd + 6686342 bytes UE4Editor!FEngineLoop::Tick() + 3876 bytes [d:\buildfarm\buildmachine_++depot+ue4-releases+4.6\engine\source\runtime\launch\private\launchengineloop.cpp:2214] UE4Editor!GuardedMain() + 479 bytes [d:\buildfarm\buildmachine_++depot+ue4-releases+4.6\engine\source\runtime\launch\private\launch.cpp:131] UE4Editor!GuardedMainWrapper() + 26 bytes [d:\buildfarm\buildmachine_++depot+ue4-releases+4.6\engine\source\runtime\launch\private\windows\launchwindows.cpp:126] UE4Editor!WinMain() + 249 bytes [d:\buildfarm\buildmachine_++depot+ue4-releases+4.6\engine\source\runtime\launch\private\windows\launchwindows.cpp:202] UE4Editor!__tmainCRTStartup() + 329 bytes [f:\dd\vctools\crt\crtw32\dllstuff\crtexe.c:618]

alt text

Product Version: Not Selected
more ▼

asked Jan 06 '15 at 07:55 AM in Bug Reports

avatar image

644 37 49 78

avatar image Wallhalla Jan 06 '15 at 08:13 AM

Trying to instantiate an abstract class is not the purpose of an abstract class, this is why it crashes.

Abstract class only describe of what its children are able to do. F.e. You have an abstract class Vehicle, there cant be no kind of object of a Vehicle in practice, but a car or an airplane which derives from this vehicle class are real object which can exists. The purpose is to set up same behaviour within Vehicle class, which both (Car and Airplane) have too. Even if the behaviour is not completely equals to each other. Example of example: ( :) ) A Vehicle has a function StartEngine. So do a car as well as an airplane, even if they do it not in the same way.

However i dont quite get what you want to achieve.

Anyways this is not a bug from epic but a bug user-created^^

avatar image JonathanADaley Jan 06 '15 at 10:07 AM

This directly causes the Editor to crash, and is reproducible. I'd call that a bug. There should at least be a warning, if not a compilation failure in a Blueprint trying to instantiate the UserWidget base class.

I only stumbled upon this bug when I wanted to not have any UMG widgets I'd created added to the screen, and also didn't want to delete the Create a Widget node.

avatar image Wallhalla Jan 06 '15 at 10:20 AM

then i would recommend to create them when they are needed, or create them were you do it right now, without an abstract class for sure, and set those widgets to be hidden by default. Keep in mind that if you use UMG somewhere does not mean that your other UI elements like Canvas or whatever will be invisible, they can stay parallel on your screen.

best regards.

I agree with you with your bug explanation in its origin meaning. And considering this telling epic this to implement the catch of wrong user input in this case makes sense to me, so forgot i said something about that ;)

(comments are locked)
10|2000 characters needed characters left
Viewable by all users

1 answer: sort voted first

Hello JonathanADaley,

I was able to reproduce this issue. I have written up a report (UE-6170) and I have submitted it to the developers for further consideration. I will provide updates with any pertinent information as it becomes available. Thank you for your information and time.

Make it a great day

more ▼

answered Jan 06 '15 at 10:24 PM

avatar image

Rudy Q ♦♦ STAFF
47.4k 545 132 525

(comments are locked)
10|2000 characters needed characters left
Viewable by all users
Your answer
toggle preview:

Up to 5 attachments (including images) can be used with a maximum of 5.2 MB each and 5.2 MB total.

Follow this question

Once you sign in you will be able to subscribe for any updates here

Answers to this question