EXCEPTION_ACCESS_VIOLATION 0x0000000000000008 when adding Animation Interface

Hey folks! Hope you’re all well-

I’ve hit a little roadblock for UE 4.27.2 in the form of a consistent crash,
Whenever I add an Animation Layer Interface to any blueprint through Class Settings, the editor freezes momentarily then quite cleanly crashes, with the error being the memory pointer in the title. The crash occurs the moment I compile the blueprint.

Same error happens even with completely fresh blueprints, new and empty interfaces not connected to anything else, and also occurs in a completely new scene and project.
I’ve reinstalled and verified the engine too

…It’s also entirely possible the problem is me, as this is my first time through the pose system

Here’s the callstack and (if it lets me) the full fat crash xml thing

UE4Editor_AnimGraph!FAnimBlueprintCompilationContext::GetHandlerInternal() [D:\Build++UE4\Sync\Engine\Source\Editor\AnimGraph\Private\AnimBlueprintCompilationContext.cpp:88]
UE4Editor_AnimGraph!UAnimGraphNode_Base::ExpandNode() [D:\Build++UE4\Sync\Engine\Source\Editor\AnimGraph\Private\AnimGraphNode_Base.cpp:40]
UE4Editor_KismetCompiler!FKismetCompilerContext::ExpansionStep() [D:\Build++UE4\Sync\Engine\Source\Editor\KismetCompiler\Private\KismetCompiler.cpp:3177]
UE4Editor_KismetCompiler!FKismetCompilerContext::ProcessOneFunctionGraph() [D:\Build++UE4\Sync\Engine\Source\Editor\KismetCompiler\Private\KismetCompiler.cpp:3801]
UE4Editor_KismetCompiler!FKismetCompilerContext::CreateFunctionList() [D:\Build++UE4\Sync\Engine\Source\Editor\KismetCompiler\Private\KismetCompiler.cpp:3959]
UE4Editor_KismetCompiler!FKismetCompilerContext::CompileClassLayout() [D:\Build++UE4\Sync\Engine\Source\Editor\KismetCompiler\Private\KismetCompiler.cpp:4145]
UE4Editor_Kismet!FBlueprintCompilationManagerImpl::FlushCompilationQueueImpl() [D:\Build++UE4\Sync\Engine\Source\Editor\Kismet\Private\BlueprintCompilationManager.cpp:1275]
UE4Editor_Kismet!FBlueprintCompilationManagerImpl::CompileSynchronouslyImpl() [D:\Build++UE4\Sync\Engine\Source\Editor\Kismet\Private\BlueprintCompilationManager.cpp:276]
UE4Editor_Kismet!FBlueprintCompilationManager::CompileSynchronously() [D:\Build++UE4\Sync\Engine\Source\Editor\Kismet\Private\BlueprintCompilationManager.cpp:3095]
UE4Editor_UnrealEd!FKismetEditorUtilities::CompileBlueprint() [D:\Build++UE4\Sync\Engine\Source\Editor\UnrealEd\Private\Kismet2\Kismet2.cpp:754]
UE4Editor_Kismet!FBlueprintEditor::Compile() [D:\Build++UE4\Sync\Engine\Source\Editor\Kismet\Private\BlueprintEditor.cpp:3643]
UE4Editor_Kismet!TBaseSPMethodDelegateInstance<0,FBlueprintEditor,0,void __cdecl(void),FDefaultDelegateUserPolicy>::ExecuteIfSafe() [D:\Build++UE4\Sync\Engine\Source\Runtime\Core\Public\Delegates\DelegateInstancesImpl.h:307]
UE4Editor_Slate!FUICommandList::ExecuteAction() [D:\Build++UE4\Sync\Engine\Source\Runtime\Slate\Private\Framework\Commands\UICommandList.cpp:102]
UE4Editor_Slate!SToolBarButtonBlock::OnClicked() [D:\Build++UE4\Sync\Engine\Source\Runtime\Slate\Private\Framework\MultiBox\SToolBarButtonBlock.cpp:301]
UE4Editor_Slate!TBaseSPMethodDelegateInstance<0,SToolBarButtonBlock,0,FReply __cdecl(void),FDefaultDelegateUserPolicy>::Execute() [D:\Build++UE4\Sync\Engine\Source\Runtime\Core\Public\Delegates\DelegateInstancesImpl.h:290]
UE4Editor_Slate!SButton::ExecuteOnClick() [D:\Build++UE4\Sync\Engine\Source\Runtime\Slate\Private\Widgets\Input\SButton.cpp:385]
UE4Editor_Slate!SButton::OnMouseButtonUp() [D:\Build++UE4\Sync\Engine\Source\Runtime\Slate\Private\Widgets\Input\SButton.cpp:304]
UE4Editor_Slate!FEventRouter::Route<FReply,FEventRouter::FToLeafmostPolicy,FPointerEvent,<lambda_cc5aea9e7377b04ce85c30c65ec3889b> >() [D:\Build++UE4\Sync\Engine\Source\Runtime\Slate\Private\Framework\Application\SlateApplication.cpp:378]
UE4Editor_Slate!FSlateApplication::RoutePointerUpEvent() [D:\Build++UE4\Sync\Engine\Source\Runtime\Slate\Private\Framework\Application\SlateApplication.cpp:4831]
UE4Editor_Slate!FSlateApplication::ProcessMouseButtonUpEvent() [D:\Build++UE4\Sync\Engine\Source\Runtime\Slate\Private\Framework\Application\SlateApplication.cpp:5372]
UE4Editor_Slate!FSlateApplication::OnMouseUp() [D:\Build++UE4\Sync\Engine\Source\Runtime\Slate\Private\Framework\Application\SlateApplication.cpp:5337]
UE4Editor_ApplicationCore!FWindowsApplication::ProcessDeferredMessage() [D:\Build++UE4\Sync\Engine\Source\Runtime\ApplicationCore\Private\Windows\WindowsApplication.cpp:2205]
UE4Editor_ApplicationCore!FWindowsApplication::DeferMessage() [D:\Build++UE4\Sync\Engine\Source\Runtime\ApplicationCore\Private\Windows\WindowsApplication.cpp:2698]
UE4Editor_ApplicationCore!FWindowsApplication::ProcessMessage() [D:\Build++UE4\Sync\Engine\Source\Runtime\ApplicationCore\Private\Windows\WindowsApplication.cpp:1881]
UE4Editor_ApplicationCore!FWindowsApplication::AppWndProc() [D:\Build++UE4\Sync\Engine\Source\Runtime\ApplicationCore\Private\Windows\WindowsApplication.cpp:905]
user32
user32
UE4Editor_ApplicationCore!FWindowsPlatformApplicationMisc::PumpMessages() [D:\Build++UE4\Sync\Engine\Source\Runtime\ApplicationCore\Private\Windows\WindowsPlatformApplicationMisc.cpp:125]
UE4Editor!FEngineLoop::Tick() [D:\Build++UE4\Sync\Engine\Source\Runtime\Launch\Private\LaunchEngineLoop.cpp:4850]
UE4Editor!GuardedMain() [D:\Build++UE4\Sync\Engine\Source\Runtime\Launch\Private\Launch.cpp:178]
UE4Editor!GuardedMainWrapper() [D:\Build++UE4\Sync\Engine\Source\Runtime\Launch\Private\Windows\LaunchWindows.cpp:137]
UE4Editor!LaunchWindowsStartup() [D:\Build++UE4\Sync\Engine\Source\Runtime\Launch\Private\Windows\LaunchWindows.cpp:273]
UE4Editor!WinMain() [D:\Build++UE4\Sync\Engine\Source\Runtime\Launch\Private\Windows\LaunchWindows.cpp:320]
UE4Editor!__scrt_common_main_seh() [d:\agent_work\5\s\src\vctools\crt\vcstartup\src\startup\exe_common.inl:288]
kernel32
ntdll
Blockquote

CrashContext.runtime-xml (133.6 KB)

I’ve crawled around in the code a little myself, but it may aswell be in Russian because I’m not nearly confident enough in it yet to say for sure
Appears to be that “IAnimBlueprintCompilerHandler” function getting upset somehow, probably because of the name it’s taking in, but I have no clue where to go from here

Any and all help thoroughly appreciated, thanks a million!

Could it be that your project files got corrupted in some way?
Try deleting:

  • Intermediate
  • Binaries
  • DerivedDataCache
  • Saved
    and then rebuilding the project.


Screenshot above is in 4.27.2 and bp compiled without errors with the interface