# UE4Editor crashes when opening a Widget Blueprint on Ubuntu **URL:** \ **Category:** UI\ **Tags:** unreal-engine, editor, crash-report, Widget, question\ **Created:** [August 18, 2016, 7:14pm UTC](https://forums.unrealengine.com/t/ue4editor-crashes-when-opening-a-widget-blueprint-on-ubuntu/367542 "2016-08-18T19:14:26Z")\ **Posts on this page:** 10\ **Page:** 1
**Author:** ![mhooo](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@mhooo](https://forums.unrealengine.com/u/mhooo)\ **Post date:** [August 18, 2016, 7:14pm UTC](https://forums.unrealengine.com/t/ue4editor-crashes-when-opening-a-widget-blueprint-on-ubuntu/367542/1 "2016-08-18T19:14:26Z")
Hello there, UE4Editor keeps crashing, whenever I open a newly created Widget in my Project, with Trace: ``` Assertion failed: (Index >= 0) & (Index < ArrayNum) [File:Runtime/Core/Public/Containers/Array.h] [Line: 833] Array index out of bounds: 12 from an array of size -1386388512[Callstack] 00 0x00007f13b398983f FLinuxPlatformStackWalk::CaptureStackBackTrace(unsigned long long*, unsigned int, void*) [Callstack] 01 0x00007f13b3867c85 FGenericPlatformStackWalk::StackWalkAndDump(char*, unsigned long, int, void*) [Callstack] 02 0x00007f13b398973a FLinuxPlatformStackWalk::StackWalkAndDump(char*, unsigned long, int, void*) [Callstack] 03 0x00007f13b39f418c FDebug::LogAssertFailedMessage(char const*, char const*, int, wchar_t const*, ...) [Callstack] 04 0x00007f139df26915 FFixedZoomLevelsContainer::GetZoomAmount(int) const [Callstack] 05 0x00007f13310f8299 TBaseSPMethodDelegateInstance::Execute() const [Callstack] 06 0x00007f1331018e05 SZoomPan::GetRelativeLayoutScale(FSlotBase const&) const [Callstack] 07 0x00007f13acaa8430 SWidget::SlatePrepass(float) [Callstack] 08 0x00007f13acaa8440 SWidget::SlatePrepass(float) [Callstack] 09 0x00007f13acaa8440 SWidget::SlatePrepass(float) [Callstack] 10 0x00007f13acaa8440 SWidget::SlatePrepass(float) [Callstack] 11 0x00007f13acaa8440 SWidget::SlatePrepass(float) [Callstack] 12 0x00007f13acaa8440 SWidget::SlatePrepass(float) [Callstack] 13 0x00007f13acaa8440 SWidget::SlatePrepass(float) [Callstack] 14 0x00007f13acaa8440 SWidget::SlatePrepass(float) [Callstack] 15 0x00007f13acaa8440 SWidget::SlatePrepass(float) [Callstack] 16 0x00007f13acaa8440 SWidget::SlatePrepass(float) [Callstack] 17 0x00007f13acaa8440 SWidget::SlatePrepass(float) [Callstack] 18 0x00007f13acaa8440 SWidget::SlatePrepass(float) [Callstack] 19 0x00007f13acaa8440 SWidget::SlatePrepass(float) [Callstack] 20 0x00007f13acaa8440 SWidget::SlatePrepass(float) [Callstack] 21 0x00007f13acaa8440 SWidget::SlatePrepass(float) [Callstack] 22 0x00007f13acaa8440 SWidget::SlatePrepass(float) [Callstack] 23 0x00007f13acaa8440 SWidget::SlatePrepass(float) [Callstack] 24 0x00007f13acaa8440 SWidget::SlatePrepass(float) [Callstack] 25 0x00007f13acaa8440 SWidget::SlatePrepass(float) [Callstack] 26 0x00007f13acaa8440 SWidget::SlatePrepass(float) [Callstack] 27 0x00007f13acaa8440 SWidget::SlatePrepass(float) [Callstack] 28 0x00007f13acaa8440 SWidget::SlatePrepass(float) [Callstack] 29 0x00007f13acaa8440 SWidget::SlatePrepass(float) [Callstack] 30 0x00007f13acaa8440 SWidget::SlatePrepass(float) [Callstack] 31 0x00007f13acaa8440 SWidget::SlatePrepass(float) [Callstack] 32 0x00007f13acaa8440 SWidget::SlatePrepass(float) [Callstack] 33 0x00007f13acaa8440 SWidget::SlatePrepass(float) [Callstack] 34 0x00007f13ad085b0e /localstorage/fast_storage/sources/UnrealEngine/Engine/Binaries/Linux/libUE4Editor-Slate.so(+0x1cdb0e) [0x7f13ad085b0e] [Callstack] 35 0x00007f13ad085d28 /localstorage/fast_storage/sources/UnrealEngine/Engine/Binaries/Linux/libUE4Editor-Slate.so(+0x1cdd28) [0x7f13ad085d28] [Callstack] 36 0x00007f13ad08551d FSlateApplication::DrawPrepass(TSharedPtr) [Callstack] 37 0x00007f13ad083411 FSlateApplication::PrivateDrawWindows(TSharedPtr) [Callstack] 38 0x00007f13ad088a52 FSlateApplication::TickApplication(float) [Callstack] 39 0x00007f13ad086b53 FSlateApplication::Tick() [Callstack] 40 0x0000000000421d94 FEngineLoop::Tick() [/localstorage/fast_storage/sources/UnrealEngine/Engine/Source/Runtime/Launch/Private/LaunchEngineLoop.cpp, line 2869] [Callstack] 41 0x00000000004256fa GuardedMain(wchar_t const*) [/localstorage/fast_storage/sources/UnrealEngine/Engine/Source/Runtime/Launch/Private/Launch.cpp, line 156] [Callstack] 42 0x00007f13a8b75d1b CommonLinuxMain(int, char**, int (*)(wchar_t const*)) [Callstack] 43 0x00007f13a8093830 /lib/x86_64-linux-gnu/libc.so.6(__libc_start_main+0xf0) [0x7f13a8093830] [Callstack] 44 0x0000000000413869 Engine/Binaries/Linux/UE4Editor(_start+0x29) [0x413869] ``` Generally, the Editor crashes a lot on Linux (ubuntu 16.04), so I suppose some state must have got corrupted last time I created a Widget. Normally creating widgets is not a Problem. I added some Logs into GraphEditor/Private/SNodePanel.cpp with the following result: - FFixedZoomLevelsContainer is only being created once with 20 elements inside its ZoomLevels Array - inside the Invokation of SZoomPan::GetRelativeLayoutScale, the destructor of FFixedZoomLevelsContainer has apparently _not_ yet been called. However, FFixedZoomLevelsContainer::ZoomLevels.Num() Member returns “-535821344”. I suspect the value is being overriden, possibly by a buffer overflow or similar. I’m not exactly sure how to best debug this and would welcome any help on this matter. I might try running valgrind to find write overflows or something, but I suspect that will take a while to run. **Edit** In an Empty Project, it appears the stacktrace is different, but still points to FFixedZoomLevelsContainer, so I assume it must be related: ``` [Callstack] 00 0x00007f6a3cfd22af FLinuxPlatformStackWalk::CaptureStackBackTrace(unsigned long long*, unsigned int, void*) [Callstack] 01 0x00007f6a3ceaf3a5 FGenericPlatformStackWalk::StackWalkAndDump(char*, unsigned long, int, void*) [Callstack] 02 0x00007f6a3cf90bf1 FLinuxCrashContext::CaptureStackTrace() [Callstack] 03 0x00007f6a321b63a0 CommonLinuxCrashHandler(FGenericCrashContext const&) [Callstack] 04 0x00007f6a3cf95464 PlatformCrashHandler(int, siginfo_t*, void*) [Callstack] 05 0x00007f6a3de1a3d0 /lib/x86_64-linux-gnu/libpthread.so.0(+0x113d0) [0x7f6a3de1a3d0] [Callstack] 06 0x00007f6a3cf60903 FText::FText(FText const&) [Callstack] 07 0x00007f6a275668ab FFixedZoomLevelsContainer::GetZoomText(int) const [Callstack] 08 0x00007f69bdfff7b8 SDesignSurface::GetZoomText() const [Callstack] 09 0x00007f69be0fcc3e TBaseSPMethodDelegateInstance::Execute() const [Callstack] 10 0x00007f6a383a6a23 TAttribute::Get() const [Callstack] 11 0x00007f6a3694b5ef FTextBlockLayout::ComputeDesiredSize(FTextBlockLayout::FWidgetArgs const&, float, FTextBlockStyle const&) [Callstack] 12 0x00007f6a3695a4f3 STextBlock::ComputeDesiredSize(float) const [Callstack] 13 0x00007f6a3615f3ed SWidget::CacheDesiredSize(float) [Callstack] 14 0x00007f6a360ec48d SWidget::SlatePrepass(float) [Callstack] 15 0x00007f6a360ec440 SWidget::SlatePrepass(float) [Callstack] 16 0x00007f6a360ec440 SWidget::SlatePrepass(float) [Callstack] 17 0x00007f6a360ec440 SWidget::SlatePrepass(float) [Callstack] 18 0x00007f6a360ec440 SWidget::SlatePrepass(float) [Callstack] 19 0x00007f6a360ec440 SWidget::SlatePrepass(float) [Callstack] 20 0x00007f6a360ec440 SWidget::SlatePrepass(float) [Callstack] 21 0x00007f6a360ec440 SWidget::SlatePrepass(float) [Callstack] 22 0x00007f6a360ec440 SWidget::SlatePrepass(float) [Callstack] 23 0x00007f6a360ec440 SWidget::SlatePrepass(float) [Callstack] 24 0x00007f6a360ec440 SWidget::SlatePrepass(float) [Callstack] 25 0x00007f6a360ec440 SWidget::SlatePrepass(float) [Callstack] 26 0x00007f6a360ec440 SWidget::SlatePrepass(float) [Callstack] 27 0x00007f6a360ec440 SWidget::SlatePrepass(float) [Callstack] 28 0x00007f6a360ec440 SWidget::SlatePrepass(float) [Callstack] 29 0x00007f6a360ec440 SWidget::SlatePrepass(float) [Callstack] 30 0x00007f6a360ec440 SWidget::SlatePrepass(float) [Callstack] 31 0x00007f6a360ec440 SWidget::SlatePrepass(float) [Callstack] 32 0x00007f6a360ec440 SWidget::SlatePrepass(float) [Callstack] 33 0x00007f6a360ec440 SWidget::SlatePrepass(float) [Callstack] 34 0x00007f6a360ec440 SWidget::SlatePrepass(float) [Callstack] 35 0x00007f6a360ec440 SWidget::SlatePrepass(float) [Callstack] 36 0x00007f6a360ec440 SWidget::SlatePrepass(float) [Callstack] 37 0x00007f6a360ec440 SWidget::SlatePrepass(float) [Callstack] 38 0x00007f6a360ec440 SWidget::SlatePrepass(float) [Callstack] 39 0x00007f6a360ec440 SWidget::SlatePrepass(float) [Callstack] 40 0x00007f6a360ec440 SWidget::SlatePrepass(float) [Callstack] 41 0x00007f6a360ec440 SWidget::SlatePrepass(float) [Callstack] 42 0x00007f6a360ec440 SWidget::SlatePrepass(float) [Callstack] 43 0x00007f6a360ec440 SWidget::SlatePrepass(float) [Callstack] 44 0x00007f6a366c9b0e /localstorage/fast_storage/sources/UnrealEngine-new-clean/Engine/Binaries/Linux/libUE4Editor-Slate.so(+0x1cdb0e) [0x7f6a366c9b0e] [Callstack] 45 0x00007f6a366c9d28 /localstorage/fast_storage/sources/UnrealEngine-new-clean/Engine/Binaries/Linux/libUE4Editor-Slate.so(+0x1cdd28) [0x7f6a366c9d28] [Callstack] 46 0x00007f6a366c951d FSlateApplication::DrawPrepass(TSharedPtr) [Callstack] 47 0x00007f6a366c7411 FSlateApplication::PrivateDrawWindows(TSharedPtr) [Callstack] 48 0x00007f6a366cca52 FSlateApplication::TickApplication(float) [Callstack] 49 0x00007f6a366cab53 FSlateApplication::Tick() [Callstack] 50 0x0000000000421d94 FEngineLoop::Tick() [/localstorage/fast_storage/sources/UnrealEngine-new-clean/Engine/Source/Runtime/Launch/Private/LaunchEngineLoop.cpp, line 2869] [Callstack] 51 0x00000000004256fa GuardedMain(wchar_t const*) [/localstorage/fast_storage/sources/UnrealEngine-new-clean/Engine/Source/Runtime/Launch/Private/Launch.cpp, line 156] [Callstack] 52 0x00007f6a321b6d1b CommonLinuxMain(int, char**, int (*)(wchar_t const*)) [Callstack] 53 0x00007f6a316d4830 /lib/x86_64-linux-gnu/libc.so.6(__libc_start_main+0xf0) [0x7f6a316d4830] [Callstack] 54 0x0000000000413869 /localstorage/fast_storage/sources/UnrealEngine-new-clean/Engine/Binaries/Linux/UE4Editor(_start+0x29) [0x413869] ``` ---
**Author:** ![anonymous\_user\_2b03d27c](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@anonymous\_user\_2b03d27c](https://forums.unrealengine.com/u/anonymous_user_2b03d27c)\ **Post date:** [August 22, 2016, 5:51pm UTC](https://forums.unrealengine.com/t/ue4editor-crashes-when-opening-a-widget-blueprint-on-ubuntu/367542/2 "2016-08-22T17:51:07Z")
Hey mhoo- Are you able to reproduce this crash in a new project without any added content? If so, does the crash occur simply by adding a widget blueprint to the content browser and then attempting to open it? Please include the steps that cause the crash to occur to help me reproduce the crash locally. ---
**Author:** ![mhooo](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@mhooo](https://forums.unrealengine.com/u/mhooo)\ **Post date:** [August 22, 2016, 7:28pm UTC](https://forums.unrealengine.com/t/ue4editor-crashes-when-opening-a-widget-blueprint-on-ubuntu/367542/3 "2016-08-22T19:28:21Z")
Yes, I can actually reproduce it on a blank project. I even re-downloaded and re-compiled the engine in a new Folder… but the crash still occurs. Steps to reproduce the crash: 1. New Project → Blank (Desktop / Console, Max. Quality, No Starter Content) 2. Wait until UE4 Restarts into new Project 3. Inside Content Browser, Click “Add New” → User Interface → Widget Blueprint 4. Rename it To BP\_Widget 5. Double Click on “BP\_Widget” inside the Content Browser 6. Wait for core dump to be generated and UE4Editor crashing Git sha: e8700ea1e56eb1cf7cebea9d68103f41ede4313a ---
**Author:** ![mhooo](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@mhooo](https://forums.unrealengine.com/u/mhooo)\ **Post date:** [August 22, 2016, 7:34pm UTC](https://forums.unrealengine.com/t/ue4editor-crashes-when-opening-a-widget-blueprint-on-ubuntu/367542/4 "2016-08-22T19:34:59Z")
Actually I just noticed: The stacktrace is slightly different this time, but still points to FFixedZoomLevelsContainer, which makes me believe it is still the same issue. Unfortunately I am unable to edit the OP to add the other stack trace. Either way, I’ll try with a clean user/clean home next. ---
**Author:** ![mhooo](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@mhooo](https://forums.unrealengine.com/u/mhooo)\ **Post date:** [August 22, 2016, 7:53pm UTC](https://forums.unrealengine.com/t/ue4editor-crashes-when-opening-a-widget-blueprint-on-ubuntu/367542/5 "2016-08-22T19:53:11Z")
Apparently the StackTrace got updated after all. Either way, I got the first StackTrace when trying the steps as in my first comment with a clean user and home dir. The UE4Engine is generating some crash information and I think, even uploading that somewhere, maybe that might help? ---
**Author:** ![anonymous\_user\_2b03d27c](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@anonymous\_user\_2b03d27c](https://forums.unrealengine.com/u/anonymous_user_2b03d27c)\ **Post date:** [August 25, 2016, 1:46pm UTC](https://forums.unrealengine.com/t/ue4editor-crashes-when-opening-a-widget-blueprint-on-ubuntu/367542/6 "2016-08-25T13:46:17Z")
Hey mhooo- I was able to reproduce the crash when opening the widget blueprint. I hadn’t originally realized that you were working in the 4.13 preview. This issue has been reported and you can follow the status of the report here: [Unreal Engine Issues and Bug Tracker (UE-35185)](https://issues.unrealengine.com/issue/UE-35185) Cheers ---
**Author:** ![RCL](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@RCL](https://forums.unrealengine.com/u/RCL)\ **Post date:** [August 25, 2016, 8:12pm UTC](https://forums.unrealengine.com/t/ue4editor-crashes-when-opening-a-widget-blueprint-on-ubuntu/367542/7 "2016-08-25T20:12:52Z")
mhoo- - could you take a look if undoing this [https://github.com/EpicGames/UnrealEngine/commit/8fba9bbdc3cc4105d7c3de24adc94f7304c7d90b](https://github.com/EpicGames/UnrealEngine/commit/8fba9bbdc3cc4105d7c3de24adc94f7304c7d90b) fixes it for you? ---
**Author:** ![mhooo](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@mhooo](https://forums.unrealengine.com/u/mhooo)\ **Post date:** [August 25, 2016, 9:16pm UTC](https://forums.unrealengine.com/t/ue4editor-crashes-when-opening-a-widget-blueprint-on-ubuntu/367542/8 "2016-08-25T21:16:14Z")
Yes, undoing the commit fixed the issue! ---
**Author:** ![anonymous\_user\_d4efcd70](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@anonymous\_user\_d4efcd70](https://forums.unrealengine.com/u/anonymous_user_d4efcd70)\ **Post date:** [September 6, 2016, 8:31pm UTC](https://forums.unrealengine.com/t/ue4editor-crashes-when-opening-a-widget-blueprint-on-ubuntu/367542/9 "2016-09-06T20:31:08Z")
I’m going to see if I can find the crash report. One of mine mentions an array being out of bounds, when trying to open a widget. ---
**Author:** ![RCL](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@RCL](https://forums.unrealengine.com/u/RCL)\ **Post date:** [September 26, 2016, 3:33pm UTC](https://forums.unrealengine.com/t/ue4editor-crashes-when-opening-a-widget-blueprint-on-ubuntu/367542/10 "2016-09-26T15:33:04Z")
This should be fixed with the following commit: [https://github.com/EpicGames/UnrealEngine/commit/358febb8e5c0a941960c4542fe926a7394e7ad53](https://github.com/EpicGames/UnrealEngine/commit/358febb8e5c0a941960c4542fe926a7394e7ad53)