Project crash on start-up

Hello, firstly I hope I posted on the right section.

Yesterday I was working on my project, everything was okay, I saved and quit, and this morning when I try to launch my project I ge a crash window with the following:


MachineId:8ACE39D548D38FF03088AB82414E7941
EpicAccountId:1e69b1a824784046b4df289a9dbbf67e

Unknown exception - code 00000001 (first/second chance not available)

"Assertion failed: (Index >= 0) & (Index < ArrayNum) [File:D:\BuildFarm\buildmachine_++depot+UE4-Releases+4.10\Engine\Source\Runtime\Core\Public\Containers\Array.h] [Line: 678]

UE4Editor_Core!FDebug::AssertFailed() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.10\engine\source\runtime\core\private\misc\outputdevice.cpp:374]
UE4Editor_Engine!FStaticLODModel::Serialize() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.10\engine\source\runtime\engine\private\skeletalmesh.cpp:1261]
UE4Editor_Engine!TIndirectArray<FStaticLODModel,FDefaultAllocator>::Serialize() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.10\engine\source\runtime\core\public\containers\array.h:3069]
UE4Editor_Engine!FSkeletalMeshResource::Serialize() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.10\engine\source\runtime\engine\private\skeletalmesh.cpp:1939]
UE4Editor_Engine!USkeletalMesh::Serialize() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.10\engine\source\runtime\engine\private\skeletalmesh.cpp:2443]
UE4Editor_CoreUObject!FLinkerLoad::Preload() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.10\engine\source\runtime\coreuobject\private\uobject\linkerload.cpp:3175]
UE4Editor_CoreUObject!EndLoad() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.10\engine\source\runtime\coreuobject\private\uobject\uobjectglobals.cpp:1245]
UE4Editor_CoreUObject!LoadPackageInternal() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.10\engine\source\runtime\coreuobject\private\uobject\uobjectglobals.cpp:1042]
UE4Editor_UnrealEd!UEditorEngine::Map_Load() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.10\engine\source\editor\unrealed\private\editorserver.cpp:2388]
UE4Editor_UnrealEd!UEditorEngine::HandleMapCommand() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.10\engine\source\editor\unrealed\private\editorserver.cpp:5897]
UE4Editor_UnrealEd!UEditorEngine::Exec() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.10\engine\source\editor\unrealed\private\editorserver.cpp:5391]
UE4Editor_UnrealEd!UUnrealEdEngine::Exec() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.10\engine\source\editor\unrealed\private\unrealedsrv.cpp:743]
UE4Editor_UnrealEd!FEditorFileUtils::LoadMap() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.10\engine\source\editor\unrealed\private\filehelpers.cpp:2014]
UE4Editor_UnrealEd!FEditorFileUtils::LoadDefaultMapAtStartup() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.10\engine\source\editor\unrealed\private\filehelpers.cpp:3215]
UE4Editor_UnrealEd!FUnrealEdMisc::OnInit() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.10\engine\source\editor\unrealed\private\unrealedmisc.cpp:299]
UE4Editor_UnrealEd!EditorInit() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.10\engine\source\editor\unrealed\private\unrealed.cpp:86]
UE4Editor!GuardedMain() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.10\engine\source\runtime\launch\private\launch.cpp:133]
UE4Editor!GuardedMainWrapper() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.10\engine\source\runtime\launch\private\windows\launchwindows.cpp:126]
UE4Editor!WinMain() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.10\engine\source\runtime\launch\private\windows\launchwindows.cpp:200]
UE4Editor!__scrt_common_main_seh() [f:\dd\vctools\crt\vcstartup\src\startup\exe_common.inl:264]
kernel32
ntdll


I don’t understand what is wrong.
Thanks

Without looking thogu the txt dump, I’ve had situation such as yours that were blueprint corruption in the end. Go into your Saved/Backup folder and rename and replace the last BPs you were working on

Thanks to answer so quickly!
The last thing I edited was a material collection, and it works well when I finished.
What is a ‘txt dump’? Does it will help to know where the crash come from?

I just ran into a similar issue. Where is this saved backup folder?