UE 5.6 Gets stuck at 35% each time

ajinkya_x · October 26, 2025, 8:05am

And this is happening only for this project, other projects they start max in 40-30 seconds.

And this started to happen when I got stuck at git commit due to LFS, then I had to revert a commit to add LFS. which corrupted the Map file. But When I started back the project I re-created Map and even PlayerCharacter BP as it got currupted. But now everytime I launch it project gets stuck at 35% about 3minutes +.

I already deleted Binaries, Intermediate, Saved, and Dervied cache folder… tried but still same.

So I decided to Validate Assets (as well Resave all) Options which crashed the project:

Assertion failed: [File:D:\build++UE5\Sync\Engine\Source\Runtime\CoreUObject\Private\UObject\LinkerLoad.cpp] [Line: 4972]
D:\UnrealProjects\AmazingBoy\Content\ParagonDrongo\Audio\Wavs\Drongo_Status_Victory_010.uasset: AssetImportData /Game/ParagonDrongo/Audio/Wavs/Drongo_Status_Victory_010.Drongo_Status_Victory_010:AssetImportData: Serial size mismatch: Got 32, Expected 187

KERNELBASE
UnrealEditor_Core!ReportAssert() [D:\build++UE5\Sync\Engine\Source\Runtime\Core\Private\Windows\WindowsPlatformCrashContext.cpp:1928]
UnrealEditor_Core!FWindowsErrorOutputDevice::Serialize() [D:\build++UE5\Sync\Engine\Source\Runtime\Core\Private\Windows\WindowsErrorOutputDevice.cpp:84]
UnrealEditor_Core!FOutputDevice::LogfImpl() [D:\build++UE5\Sync\Engine\Source\Runtime\Core\Private\Misc\OutputDevice.cpp:81]
UnrealEditor_Core!AssertFailedImplV() [D:\build++UE5\Sync\Engine\Source\Runtime\Core\Private\Misc\AssertionMacros.cpp:167]
UnrealEditor_Core!FDebug::AssertFailed() [D:\build++UE5\Sync\Engine\Source\Runtime\Core\Private\Misc\AssertionMacros.cpp:738]
UnrealEditor_CoreUObject!FLinkerLoad::Preload() [D:\build++UE5\Sync\Engine\Source\Runtime\CoreUObject\Private\UObject\LinkerLoad.cpp:4972]
UnrealEditor_CoreUObject!FAsyncPackage2::PreloadLinkerLoadExports() [D:\build++UE5\Sync\Engine\Source\Runtime\CoreUObject\Private\Serialization\AsyncLoading2.cpp:6865]
UnrealEditor_CoreUObject!FAsyncPackage2::Event_PreloadLinkerLoadExports() [D:\build++UE5\Sync\Engine\Source\Runtime\CoreUObject\Private\Serialization\AsyncLoading2.cpp:7272]
UnrealEditor_CoreUObject!FEventLoadNode2::Execute() [D:\build++UE5\Sync\Engine\Source\Runtime\CoreUObject\Private\Serialization\AsyncLoading2.cpp:5713]
UnrealEditor_CoreUObject!FAsyncLoadEventQueue2::ExecuteSyncLoadEvents() [D:\build++UE5\Sync\Engine\Source\Runtime\CoreUObject\Private\Serialization\AsyncLoading2.cpp:5920]
UnrealEditor_CoreUObject!FAsyncLoadingThread2::ProcessAsyncLoadingFromGameThread() [D:\build++UE5\Sync\Engine\Source\Runtime\CoreUObject\Private\Serialization\AsyncLoading2.cpp:9215]
UnrealEditor_CoreUObject!FAsyncLoadingThread2::TickAsyncLoadingFromGameThread() [D:\build++UE5\Sync\Engine\Source\Runtime\CoreUObject\Private\Serialization\AsyncLoading2.cpp:9565]
UnrealEditor_CoreUObject!FAsyncLoadingThread2::FlushLoading() [D:\build++UE5\Sync\Engine\Source\Runtime\CoreUObject\Private\Serialization\AsyncLoading2.cpp:11242]
UnrealEditor_CoreUObject!FlushAsyncLoading() [D:\build++UE5\Sync\Engine\Source\Runtime\CoreUObject\Private\Serialization\AsyncPackageLoader.cpp:362]
UnrealEditor_CoreUObject!FlushAsyncLoading() [D:\build++UE5\Sync\Engine\Source\Runtime\CoreUObject\Private\Serialization\AsyncPackageLoader.cpp:331]
UnrealEditor_CoreUObject!LoadPackageInternal() [D:\build++UE5\Sync\Engine\Source\Runtime\CoreUObject\Private\UObject\UObjectGlobals.cpp:1771]
UnrealEditor_CoreUObject!LoadPackage() [D:\build++UE5\Sync\Engine\Source\Runtime\CoreUObject\Private\UObject\UObjectGlobals.cpp:2135]
UnrealEditor_CoreUObject!LoadPackage() [D:\build++UE5\Sync\Engine\Source\Runtime\CoreUObject\Private\UObject\UObjectGlobals.cpp:2111]
UnrealEditor_DataValidation!FAssetData::FastGetAsset() [D:\build++UE5\Sync\Engine\Source\Runtime\CoreUObject\Public\AssetRegistry\AssetData.h:534]
UnrealEditor_DataValidation!UEditorValidatorSubsystem::ValidateAssetsInternal() [D:\build++UE5\Sync\Engine\Plugins\Editor\DataValidation\Source\DataValidation\Private\EditorValidatorSubsystem.cpp:588]
UnrealEditor_DataValidation!UEditorValidatorSubsystem::ValidateAssetsWithSettings() [D:\build++UE5\Sync\Engine\Plugins\Editor\DataValidation\Source\DataValidation\Private\EditorValidatorSubsystem.cpp:427]
UnrealEditor_DataValidation!FDataValidationModule::ValidateAssets() [D:\build++UE5\Sync\Engine\Plugins\Editor\DataValidation\Source\DataValidation\Private\DataValidationModule.cpp:339]
UnrealEditor_DataValidation!FDataValidationModule::ValidateFolders() [D:\build++UE5\Sync\Engine\Plugins\Editor\DataValidation\Source\DataValidation\Private\DataValidationModule.cpp:372]
UnrealEditor_DataValidation!FMaterialEditorValidationPlatformCustomization::CustomizeHeader'::2’::<lambda_4>::operator()() [D:\build++UE5\Sync\Engine\Plugins\Editor\DataValidation\Source\DataValidation\Private\DataValidationModule.cpp:238]
UnrealEditor_DataValidation!TBaseFunctorDelegateInstance<FText __cdecl(void),FDefaultDelegateUserPolicy,TFunction<FText __cdecl(void)> >::ExecuteIfSafe() [D:\build++UE5\Sync\Engine\Source\Runtime\Core\Public\Delegates\DelegateInstancesImpl.h:894]
UnrealEditor_ToolMenus!TBaseFunctorDelegateInstance<EVisibility __cdecl(void),FDefaultDelegateUserPolicy,TFunction<EVisibility __cdecl(void)> >::ExecuteIfSafe() [D:\build++UE5\Sync\Engine\Source\Runtime\Core\Public\Delegates\DelegateInstancesImpl.h:892]
UnrealEditor_Slate!FUIAction::Execute() [D:\build++UE5\Sync\Engine\Source\Runtime\Slate\Public\Framework\Commands\UIAction.h:139]
UnrealEditor_Slate!SMenuEntryBlock::OnClicked() [D:\build++UE5\Sync\Engine\Source\Runtime\Slate\Private\Framework\MultiBox\SMenuEntryBlock.cpp:1197]
UnrealEditor_Slate!SMenuEntryBlock::OnMenuItemButtonClicked() [D:\build++UE5\Sync\Engine\Source\Runtime\Slate\Private\Framework\MultiBox\SMenuEntryBlock.cpp:1148]
UnrealEditor_Slate!V::TBaseSPMethodDelegateInstance::Execute() [D:\build++UE5\Sync\Engine\Source\Runtime\Core\Public\Delegates\DelegateInstancesImpl.h:292]
UnrealEditor_Slate!SButton::ExecuteOnClick() [D:\build++UE5\Sync\Engine\Source\Runtime\Slate\Private\Widgets\Input\SButton.cpp:495]
UnrealEditor_Slate!SButton::OnMouseButtonUp() [D:\build++UE5\Sync\Engine\Source\Runtime\Slate\Private\Widgets\Input\SButton.cpp:419]
UnrealEditor_Slate!SMenuEntryButton::OnMouseButtonUp() [D:\build++UE5\Sync\Engine\Source\Runtime\Slate\Private\Framework\MultiBox\SMenuEntryBlock.cpp:447]
UnrealEditor_Slate!TArray<TWeakPtr<TAnimatedAttributeBase,1>,TSizedDefaultAllocator<32> >::Remove'::2’::<lambda_1>::operator()() [D:\build++UE5\Sync\Engine\Source\Runtime\Slate\Private\Framework\Application\SlateApplication.cpp:5367]
UnrealEditor_Slate!UE::Core::Private::ReallocTo<3,TSizedHeapAllocator<32,FMemory>::ForAnyElementType>() [D:\build++UE5\Sync\Engine\Source\Runtime\Slate\Private\Framework\Application\SlateApplication.cpp:456]
UnrealEditor_Slate!FSlateApplication::RoutePointerUpEvent() [D:\build++UE5\Sync\Engine\Source\Runtime\Slate\Private\Framework\Application\SlateApplication.cpp:5353]
UnrealEditor_Slate!FSlateApplication::ProcessMouseButtonUpEvent() [D:\build++UE5\Sync\Engine\Source\Runtime\Slate\Private\Framework\Application\SlateApplication.cpp:5938]
UnrealEditor_Slate!FSlateApplication::OnMouseUp() [D:\build++UE5\Sync\Engine\Source\Runtime\Slate\Private\Framework\Application\SlateApplication.cpp:5894]
UnrealEditor_ApplicationCore!FWindowsApplication::ProcessDeferredMessage() [D:\build++UE5\Sync\Engine\Source\Runtime\ApplicationCore\Private\Windows\WindowsApplication.cpp:3052]
UnrealEditor_ApplicationCore!FWindowsApplication::DeferMessage() [D:\build++UE5\Sync\Engine\Source\Runtime\ApplicationCore\Private\Windows\WindowsApplication.cpp:3570]
UnrealEditor_ApplicationCore!FWindowsApplication::ProcessMessage() [D:\build++UE5\Sync\Engine\Source\Runtime\ApplicationCore\Private\Windows\WindowsApplication.cpp:2725]
UnrealEditor_ApplicationCore!FWindowsApplication::AppWndProc() [D:\build++UE5\Sync\Engine\Source\Runtime\ApplicationCore\Private\Windows\WindowsApplication.cpp:1722]
user32
user32
UnrealEditor_ApplicationCore!FWindowsPlatformApplicationMisc::PumpMessages() [D:\build++UE5\Sync\Engine\Source\Runtime\ApplicationCore\Private\Windows\WindowsPlatformApplicationMisc.cpp:145]
UnrealEditor!FEngineLoop::Tick() [D:\build++UE5\Sync\Engine\Source\Runtime\Launch\Private\LaunchEngineLoop.cpp:5554]
UnrealEditor!GuardedMain() [D:\build++UE5\Sync\Engine\Source\Runtime\Launch\Private\Launch.cpp:187]
UnrealEditor!GuardedMainWrapper() [D:\build++UE5\Sync\Engine\Source\Runtime\Launch\Private\Windows\LaunchWindows.cpp:128]
UnrealEditor!LaunchWindowsStartup() [D:\build++UE5\Sync\Engine\Source\Runtime\Launch\Private\Windows\LaunchWindows.cpp:282]
UnrealEditor!WinMain() [D:\build++UE5\Sync\Engine\Source\Runtime\Launch\Private\Windows\LaunchWindows.cpp:339]
UnrealEditor!__scrt_common_main_seh() [D:\a_work\1\s\src\vctools\crt\vcstartup\src\startup\exe_common.inl:288]
kernel32
ntdll

ajinkya_x · October 26, 2025, 9:10am

I fixed it.

1. `git lfs pull`
2. Deleted Binaries, DerivedDataCache, Intermediate and Saved folder
3. Re-downloaded Paragon Drongo assets and did the OVERWRITE.
4. when asked by UE editor recompiled. works fine now

ajinkya_x · October 26, 2025, 9:39am

After re-download there was a massive loads files edited and created so my git had to pushed again. So I did it correctly this time. (GIT is better than Diversion IMO) It just last time I didn’t install lfs correctly before pushing. Of-course the git compression and writing step a bit long time for first time.