Open a migrated blueprint crashes the editor everytime

[3dstuff]

Hello please anyone can help?
I migrated a blueprint class from ue4.26 to ue5.3 but when i try to open that blueprint the editor crashes everytime, no problems opening it in 4.26, i try delete some references in 4.26 and migrate more times the modified blueprint but with no luck, i am not able to find what cause this crash, this is the error i got, thank you in advance to who can help:

Unhandled Exception: EXCEPTION_ACCESS_VIOLATION reading address 0x0000000000000010

UnrealEditor_SubobjectDataInterface!FChildSubobjectDataFactory::ShouldCreateSubobjectData() [D:\build++UE5\Sync\Engine\Source\Editor\SubobjectDataInterface\Private\ChildSubobjectDataFactory.cpp:25]
UnrealEditor_SubobjectDataInterface!FSubobjectFactoryManager::FindFactoryToUse() [D:\build++UE5\Sync\Engine\Source\Editor\SubobjectDataInterface\Public\SubobjectDataFactory.h:98]
UnrealEditor_SubobjectDataInterface!USubobjectDataSubsystem::CreateSubobjectData() [D:\build++UE5\Sync\Engine\Source\Editor\SubobjectDataInterface\Private\SubobjectDataSubsystem.cpp:2588]
UnrealEditor_SubobjectDataInterface!USubobjectDataSubsystem::FactoryCreateSubobjectDataWithParent() [D:\build++UE5\Sync\Engine\Source\Editor\SubobjectDataInterface\Private\SubobjectDataSubsystem.cpp:2622]
UnrealEditor_SubobjectDataInterface!USubobjectDataSubsystem::FactoryCreateInheritedBpSubobject() [D:\build++UE5\Sync\Engine\Source\Editor\SubobjectDataInterface\Private\SubobjectDataSubsystem.cpp:2710]
UnrealEditor_SubobjectDataInterface!USubobjectDataSubsystem::FactoryCreateInheritedBpSubobject() [D:\build++UE5\Sync\Engine\Source\Editor\SubobjectDataInterface\Private\SubobjectDataSubsystem.cpp:2704]
UnrealEditor_SubobjectDataInterface!USubobjectDataSubsystem::GatherSubobjectData() [D:\build++UE5\Sync\Engine\Source\Editor\SubobjectDataInterface\Private\SubobjectDataSubsystem.cpp:324]
UnrealEditor_SubobjectEditor!SSubobjectEditor::UpdateTree() [D:\build++UE5\Sync\Engine\Source\Editor\SubobjectEditor\Private\SSubobjectEditor.cpp:2485]
UnrealEditor_SubobjectEditor!SSubobjectBlueprintEditor::Construct() [D:\build++UE5\Sync\Engine\Source\Editor\SubobjectEditor\Private\SSubobjectBlueprintEditor.cpp:179]
UnrealEditor_Kismet!TSlateDecl<SSubobjectBlueprintEditor,RequiredArgs::T0RequiredArgs>::operator<<=() [D:\build++UE5\Sync\Engine\Source\Runtime\SlateCore\Public\Widgets\DeclarativeSyntaxSupport.h:976]
UnrealEditor_Kismet!FBlueprintEditor::CreateSubobjectEditors() [D:\build++UE5\Sync\Engine\Source\Editor\Kismet\Private\BlueprintEditor.cpp:2964]
UnrealEditor_Kismet!FBlueprintEditor::CreateDefaultTabContents() [D:\build++UE5\Sync\Engine\Source\Editor\Kismet\Private\BlueprintEditor.cpp:2954]
UnrealEditor_Kismet!FBlueprintEditor::CommonInitialization() [D:\build++UE5\Sync\Engine\Source\Editor\Kismet\Private\BlueprintEditor.cpp:2030]
UnrealEditor_Kismet!FBlueprintEditor::InitBlueprintEditor() [D:\build++UE5\Sync\Engine\Source\Editor\Kismet\Private\BlueprintEditor.cpp:2364]
UnrealEditor_Kismet!FBlueprintEditorModule::CreateBlueprintEditor() [D:\build++UE5\Sync\Engine\Source\Editor\Kismet\Private\BlueprintEditorModule.cpp:307]
UnrealEditor_Kismet!FBlueprintEditorModule::CreateBlueprintEditor() [D:\build++UE5\Sync\Engine\Source\Editor\Kismet\Private\BlueprintEditorModule.cpp:298]
UnrealEditor_EngineAssetDefinitions!UAssetDefinition_Blueprint::OpenAssets() [D:\build++UE5\Sync\Engine\Plugins\Editor\EngineAssetDefinitions\Source\Private\Script\AssetDefinition_Blueprint.cpp:136]
UnrealEditor_AssetTools!FAssetDefinitionProxy::OpenAssetEditor() [D:\build++UE5\Sync\Engine\Source\Developer\AssetTools\Private\AssetTools.cpp:244]
UnrealEditor_UnrealEd!UAssetEditorSubsystem::OpenEditorForAsset() [D:\build++UE5\Sync\Engine\Source\Editor\UnrealEd\Private\Subsystems\AssetEditorSubsystem.cpp:579]
UnrealEditor_UnrealEd!UAssetEditorSubsystem::OpenEditorForAssets_Advanced() [D:\build++UE5\Sync\Engine\Source\Editor\UnrealEd\Private\Subsystems\AssetEditorSubsystem.cpp:645]
UnrealEditor_UnrealEd!UAssetEditorSubsystem::OpenEditorForAssets() [D:\build++UE5\Sync\Engine\Source\Editor\UnrealEd\Private\Subsystems\AssetEditorSubsystem.cpp:761]
UnrealEditor_ContentBrowserAssetDataSource!ContentBrowserAssetData::EditOrPreviewAssetFileItems() [D:\build++UE5\Sync\Engine\Plugins\Editor\ContentBrowser\ContentBrowserAssetDataSource\Source\ContentBrowserAssetDataSource\Private\ContentBrowserAssetDataCore.cpp:372]
UnrealEditor_ContentBrowserAssetDataSource!ContentBrowserAssetData::EditOrPreviewItems() [D:\build++UE5\Sync\Engine\Plugins\Editor\ContentBrowser\ContentBrowserAssetDataSource\Source\ContentBrowserAssetDataSource\Private\ContentBrowserAssetDataCore.cpp:417]
UnrealEditor_ContentBrowserAssetDataSource!UContentBrowserAssetDataSource::BulkEditItems() [D:\build++UE5\Sync\Engine\Plugins\Editor\ContentBrowser\ContentBrowserAssetDataSource\Source\ContentBrowserAssetDataSource\Private\ContentBrowserAssetDataSource.cpp:2200]
UnrealEditor_ContentBrowser!SContentBrowser::OnItemsActivated() [D:\build++UE5\Sync\Engine\Source\Editor\ContentBrowser\Private\SContentBrowser.cpp:3141]
UnrealEditor_ContentBrowser!TBaseSPMethodDelegateInstance<0,SContentBrowser,1,void __cdecl(TArrayView<FContentBrowserItem const ,int>,enum EAssetTypeActivationMethod::Type),FDefaultDelegateUserPolicy>::Execute() [D:\build++UE5\Sync\Engine\Source\Runtime\Core\Public\Delegates\DelegateInstancesImpl.h:281]
UnrealEditor_ContentBrowser!SAssetView::OnListMouseButtonDoubleClick() [D:\build++UE5\Sync\Engine\Source\Editor\ContentBrowser\Private\SAssetView.cpp:4081]
UnrealEditor_ContentBrowser!TBaseSPMethodDelegateInstance<0,SAssetView,1,void __cdecl(TSharedPtr<FAssetViewItem,1>),FDefaultDelegateUserPolicy>::ExecuteIfSafe() [D:\build++UE5\Sync\Engine\Source\Runtime\Core\Public\Delegates\DelegateInstancesImpl.h:298]
UnrealEditor_ContentBrowser!TDelegate<void __cdecl(TSharedPtr<FAssetViewItem,1>),FDefaultDelegateUserPolicy>::ExecuteIfBound<void,0>() [D:\build++UE5\Sync\Engine\Source\Runtime\Core\Public\Delegates\DelegateSignatureImpl.inl:570]
UnrealEditor_ContentBrowser!SListView<TSharedPtr<FAssetViewItem,1> >::Private_OnItemDoubleClicked() [D:\build++UE5\Sync\Engine\Source\Runtime\Slate\Public\Widgets\Views\SListView.h:1122]
UnrealEditor_ContentBrowser!STableRow<TSharedPtr<FAssetViewItem,1> >::OnMouseButtonDoubleClick() [D:\build++UE5\Sync\Engine\Source\Runtime\Slate\Public\Widgets\Views\STableRow.h:423]
UnrealEditor_Slate!FEventRouter::Route<FReply,FEventRouter::FBubblePolicy,FPointerEvent,FSlateApplication::RoutePointerDoubleClickEvent'::2’::<lambda_1> >() [D:\build++UE5\Sync\Engine\Source\Runtime\Slate\Private\Framework\Application\SlateApplication.cpp:442]
UnrealEditor_Slate!FSlateApplication::RoutePointerDoubleClickEvent() [D:\build++UE5\Sync\Engine\Source\Runtime\Slate\Private\Framework\Application\SlateApplication.cpp:5700]
UnrealEditor_Slate!FSlateApplication::ProcessMouseButtonDoubleClickEvent() [D:\build++UE5\Sync\Engine\Source\Runtime\Slate\Private\Framework\Application\SlateApplication.cpp:5685]
UnrealEditor_Slate!FSlateApplication::OnMouseDoubleClick() [D:\build++UE5\Sync\Engine\Source\Runtime\Slate\Private\Framework\Application\SlateApplication.cpp:5648]
UnrealEditor_ApplicationCore!FWindowsApplication::ProcessDeferredMessage() [D:\build++UE5\Sync\Engine\Source\Runtime\ApplicationCore\Private\Windows\WindowsApplication.cpp:2235]
UnrealEditor_ApplicationCore!FWindowsApplication::DeferMessage() [D:\build++UE5\Sync\Engine\Source\Runtime\ApplicationCore\Private\Windows\WindowsApplication.cpp:2738]
UnrealEditor_ApplicationCore!FWindowsApplication::ProcessMessage() [D:\build++UE5\Sync\Engine\Source\Runtime\ApplicationCore\Private\Windows\WindowsApplication.cpp:1099]
UnrealEditor_ApplicationCore!FWindowsApplication::AppWndProc() [D:\build++UE5\Sync\Engine\Source\Runtime\ApplicationCore\Private\Windows\WindowsApplication.cpp:937]
user32
user32
UnrealEditor_ApplicationCore!FWindowsPlatformApplicationMisc::PumpMessages() [D:\build++UE5\Sync\Engine\Source\Runtime\ApplicationCore\Private\Windows\WindowsPlatformApplicationMisc.cpp:148]
UnrealEditor!FEngineLoop::Tick() [D:\build++UE5\Sync\Engine\Source\Runtime\Launch\Private\LaunchEngineLoop.cpp:5749]
UnrealEditor!GuardedMain() [D:\build++UE5\Sync\Engine\Source\Runtime\Launch\Private\Launch.cpp:188]
UnrealEditor!GuardedMainWrapper() [D:\build++UE5\Sync\Engine\Source\Runtime\Launch\Private\Windows\LaunchWindows.cpp:118]
UnrealEditor!LaunchWindowsStartup() [D:\build++UE5\Sync\Engine\Source\Runtime\Launch\Private\Windows\LaunchWindows.cpp:258]
UnrealEditor!WinMain() [D:\build++UE5\Sync\Engine\Source\Runtime\Launch\Private\Windows\LaunchWindows.cpp:298]
UnrealEditor!__scrt_common_main_seh() [D:\a_work\1\s\src\vctools\crt\vcstartup\src\startup\exe_common.inl:288]
kernel32
ntdll

[Nawrot]

If you have CONSTRUCTION graph in there, disconnect it before migrating. Usually crashes on importing or opening are caused by construction script, or in widgets by OnConstruct.

Also sometimes crash is caused by functions from blueprints function library (happened once to me so i mention it).

Generally missing or wrong pointers cause it, however it is quite hard to do that in blueprints only.

[3dstuff]

Thank you, i will try and let you know in a second.

[3dstuff]

disconnected construction script node, migrated, but unfortunately it crashes again

[Nawrot]

Since you have source blueprints in old project, you are about to go on a hunt for elephant in africa:

• split africa into two parts
• check which part has elephant.
• focus on part of africa that has elephant
• repeat from first step
• until you have really small area of africa that has elephant inside, trap it and take to England

So: copy your blueprints in old project and:

• migrate it (that new copy) and see if it crashes
• if it crashes, delete big part of code there (in source)
• migrate and try if it crashes again
• if it does not you know elephant is in part you just deleted
• if it crashes go back to step 1 (ie copy that blueprint from unchanged version), delete another part of blueprint, migrate.

Repeat until you have idea what is going on.

Ps. use comment to mark parts you checcked for elephant.
pps. You may remove all references th\at are used as default values in blueprint. So make some default meshes and textures/materials. Make sure t hat nothing except those default.dummy assets is referenced from that blueprint. (reference viewer it) And do nopt reference/use anything that is in engine folders or in plugins.

[3dstuff]

OK i search that elephant, he is not small, i m still buying ticket for Africa ;).
Will let you know.
Thank you

[3dstuff]

I tryed to delete almost all, i migrate but nothing, another crash, but i noted that only 2 things i can’t really delete(see photo below) they are like ghost components, this “arrow9” and “billboard9”, they have a strange icon, not a normal arrow or billboard icon, and i can’t delete them, they haven’t a detail panel, they are not declared anywhere, and they are not in the viewport, no coordinates nothing, how to delete them??for sure the problem are they. Why they are there? In UE4.26 they not cause any problems, i can’t delete them in 4.26 also, ever if they are like i described above, in UE5.3 they probably cause the crash, because in this blueprint they are the only things remained.

[Nawrot]

Try fixing redirectors in 4.xx project. Those may be leftovers from some corrupted version of blueprint.

If this does not help, create empty blueprint of same class, in 4.xx and copy paste all stuff. Then you will get ghostly nodes for get and set variables, just go over blueprint click on them and recreate variables.

You can also try this (on copy of that blueprint in 4.xx):

• create same class of blueprint. Name it foe eg: BP_ParentClass
• reparent your crashing blueprint (copy of it!) to be child of that BP_ParentClass, this either will crash or hopefully unlock/remove corrupted components.
• change your reparented blueprint into base class back.

EDIT:

try this option (add to shortcut that starts editor):

-NoLoadStartupPackages

[3dstuff]

Thank you so much Nawrot, you point me in the right direction, now my custom train works finally!
This is the blueprint i migrated to 5.3.
https://www.youtube.com/watch?v=6v4eFW7w3CU