Today, I had this error again but also Assertion failed: IsUnlocked() - it could only be resolved by deleting the Intermediate folder.
[2024.05.03-14.15.57:485][581]UATHelper: Packaging (Windows): LogWindows: Error: begin: stack for UAT
[2024.05.03-14.15.57:485][581]UATHelper: Packaging (Windows): LogWindows: Error: === Critical error: ===
[2024.05.03-14.15.57:485][581]UATHelper: Packaging (Windows): LogWindows: Error:
[2024.05.03-14.15.57:485][581]UATHelper: Packaging (Windows): LogWindows: Error: Assertion failed: IsUnlocked() [File:F:\UE\Engine\UE_5.3_Source\Engine\Source\Runtime\CoreUObject\Private\Serialization\BulkData.cpp] [Line: 908]
[2024.05.03-14.15.57:485][581]UATHelper: Packaging (Windows): LogWindows: Error:
[2024.05.03-14.15.57:485][581]UATHelper: Packaging (Windows): LogWindows: Error:
[2024.05.03-14.15.57:485][581]UATHelper: Packaging (Windows): LogWindows: Error:
[2024.05.03-14.15.57:485][581]UATHelper: Packaging (Windows): LogWindows: Error: [Callstack] 0x00007ffe7062f086 UnrealEditor-Engine.dll!GetDDCBuiltData<FChaosDerivedDataCooker>() [F:\UE\Engine\UE_5.3_Source\Engine\Source\Runtime\Engine\Private\PhysicsEngine\BodySetup.cpp:1366]
[2024.05.03-14.15.57:485][581]UATHelper: Packaging (Windows): LogWindows: Error: [Callstack] 0x00007ffe706adc59 UnrealEditor-Engine.dll!UBodySetup::GetCookedData() [F:\UE\Engine\UE_5.3_Source\Engine\Source\Runtime\Engine\Private\PhysicsEngine\BodySetup.cpp:1420]
[2024.05.03-14.15.57:485][581]UATHelper: Packaging (Windows): LogWindows: Error: [Callstack] 0x00007ffe706caf8c UnrealEditor-Engine.dll!UBodySetup::IsCachedCookedPlatformDataLoaded() [F:\UE\Engine\UE_5.3_Source\Engine\Source\Runtime\Engine\Private\PhysicsEngine\BodySetup.cpp:1224]
[2024.05.03-14.15.57:485][581]UATHelper: Packaging (Windows): LogWindows: Error: [Callstack] 0x00007ffe6c93d575 UnrealEditor-UnrealEd.dll!UCookOnTheFlyServer::RouteIsCachedCookedPlatformDataLoaded() [F:\UE\Engine\UE_5.3_Source\Engine\Source\Editor\UnrealEd\Private\CookOnTheFlyServer.cpp:12009]
[2024.05.03-14.15.57:485][581]UATHelper: Packaging (Windows): LogWindows: Error: [Callstack] 0x00007ffe6c8d454b UnrealEditor-UnrealEd.dll!UCookOnTheFlyServer::CallBeginCacheOnObjects() [F:\UE\Engine\UE_5.3_Source\Engine\Source\Editor\UnrealEd\Private\CookOnTheFlyServer.cpp:3809]
[2024.05.03-14.15.57:485][581]UATHelper: Packaging (Windows): LogWindows: Error: [Callstack] 0x00007ffe6c8cefdd UnrealEditor-UnrealEd.dll!UCookOnTheFlyServer::BeginCacheObjectsToMove() [F:\UE\Engine\UE_5.3_Source\Engine\Source\Editor\UnrealEd\Private\CookOnTheFlyServer.cpp:3346]
[2024.05.03-14.15.57:485][581]UATHelper: Packaging (Windows): LogWindows: Error: [Callstack] 0x00007ffe6c922854 UnrealEditor-UnrealEd.dll!UCookOnTheFlyServer::PrepareSaveGeneratedPackage() [F:\UE\Engine\UE_5.3_Source\Engine\Source\Editor\UnrealEd\Private\CookOnTheFlyServer.cpp:3198]
[2024.05.03-14.15.57:485][581]UATHelper: Packaging (Windows): LogWindows: Error: [Callstack] 0x00007ffe6c922902 UnrealEditor-UnrealEd.dll!UCookOnTheFlyServer::PrepareSaveGeneratedPackage() [F:\UE\Engine\UE_5.3_Source\Engine\Source\Editor\UnrealEd\Private\CookOnTheFlyServer.cpp:3221]
[2024.05.03-14.15.57:485][581]UATHelper: Packaging (Windows): LogWindows: Error: [Callstack] 0x00007ffe6c922d75 UnrealEditor-UnrealEd.dll!UCookOnTheFlyServer::PrepareSaveInternal() [F:\UE\Engine\UE_5.3_Source\Engine\Source\Editor\UnrealEd\Private\CookOnTheFlyServer.cpp:3746]
[2024.05.03-14.15.57:485][581]UATHelper: Packaging (Windows): LogWindows: Error: [Callstack] 0x00007ffe6c9226bb UnrealEditor-UnrealEd.dll!UCookOnTheFlyServer::PrepareSave() [F:\UE\Engine\UE_5.3_Source\Engine\Source\Editor\UnrealEd\Private\CookOnTheFlyServer.cpp:3596]
[2024.05.03-14.15.57:485][581]UATHelper: Packaging (Windows): LogWindows: Error: [Callstack] 0x00007ffe6c928136 UnrealEditor-UnrealEd.dll!UCookOnTheFlyServer::PumpSaves() [F:\UE\Engine\UE_5.3_Source\Engine\Source\Editor\UnrealEd\Private\CookOnTheFlyServer.cpp:4364]
[2024.05.03-14.15.57:485][581]UATHelper: Packaging (Windows): LogWindows: Error: [Callstack] 0x00007ffe6c948247 UnrealEditor-UnrealEd.dll!UCookOnTheFlyServer::TickMainCookLoop() [F:\UE\Engine\UE_5.3_Source\Engine\Source\Editor\UnrealEd\Private\CookOnTheFlyServer.cpp:1412]
[2024.05.03-14.15.57:485][581]UATHelper: Packaging (Windows): LogWindows: Error: [Callstack] 0x00007ffe6c947aa7 UnrealEditor-UnrealEd.dll!UCookOnTheFlyServer::TickCookByTheBook() [F:\UE\Engine\UE_5.3_Source\Engine\Source\Editor\UnrealEd\Private\CookOnTheFlyServer.cpp:1294]
[2024.05.03-14.15.57:485][581]UATHelper: Packaging (Windows): LogWindows: Error: [Callstack] 0x00007ffe6c639c40 UnrealEditor-UnrealEd.dll!UCookCommandlet::RunCookByTheBookCook() [F:\UE\Engine\UE_5.3_Source\Engine\Source\Editor\UnrealEd\Private\Commandlets\CookCommandlet.cpp:543]
[2024.05.03-14.15.57:485][581]UATHelper: Packaging (Windows): LogWindows: Error: [Callstack] 0x00007ffe6c5f3323 UnrealEditor-UnrealEd.dll!UCookCommandlet::CookByTheBook() [F:\UE\Engine\UE_5.3_Source\Engine\Source\Editor\UnrealEd\Private\Commandlets\CookCommandlet.cpp:504]
[2024.05.03-14.15.57:485][581]UATHelper: Packaging (Windows): LogWindows: Error: [Callstack] 0x00007ffe6c61255f UnrealEditor-UnrealEd.dll!UCookCommandlet::Main() [F:\UE\Engine\UE_5.3_Source\Engine\Source\Editor\UnrealEd\Private\Commandlets\CookCommandlet.cpp:243]
[2024.05.03-14.15.57:485][581]UATHelper: Packaging (Windows): LogWindows: Error: [Callstack] 0x00007ff736b3733f UnrealEditor-Cmd.exe!FEngineLoop::PreInitPostStartupScreen() [F:\UE\Engine\UE_5.3_Source\Engine\Source\Runtime\Launch\Private\LaunchEngineLoop.cpp:4136]
[2024.05.03-14.15.57:485][581]UATHelper: Packaging (Windows): LogWindows: Error: [Callstack] 0x00007ff736b2cfb6 UnrealEditor-Cmd.exe!GuardedMain() [F:\UE\Engine\UE_5.3_Source\Engine\Source\Runtime\Launch\Private\Launch.cpp:140]
[2024.05.03-14.15.57:496][581]UATHelper: Packaging (Windows): LogWindows: Error: [Callstack] 0x00007ff736b2d37a UnrealEditor-Cmd.exe!GuardedMainWrapper() [F:\UE\Engine\UE_5.3_Source\Engine\Source\Runtime\Launch\Private\Windows\LaunchWindows.cpp:118]
[2024.05.03-14.15.57:496][581]UATHelper: Packaging (Windows): LogWindows: Error: [Callstack] 0x00007ff736b30854 UnrealEditor-Cmd.exe!LaunchWindowsStartup() [F:\UE\Engine\UE_5.3_Source\Engine\Source\Runtime\Launch\Private\Windows\LaunchWindows.cpp:258]
[2024.05.03-14.15.57:496][581]UATHelper: Packaging (Windows): LogWindows: Error: [Callstack] 0x00007ff736b46984 UnrealEditor-Cmd.exe!WinMain() [F:\UE\Engine\UE_5.3_Source\Engine\Source\Runtime\Launch\Private\Windows\LaunchWindows.cpp:298]
[2024.05.03-14.15.57:496][581]UATHelper: Packaging (Windows): LogWindows: Error: [Callstack] 0x00007ff736b48eb6 UnrealEditor-Cmd.exe!__scrt_common_main_seh() [D:\a\_work\1\s\src\vctools\crt\vcstartup\src\startup\exe_common.inl:288]
[2024.05.03-14.15.57:496][581]UATHelper: Packaging (Windows): LogWindows: Error: [Callstack] 0x00007ffecd427344 KERNEL32.DLL!UnknownFunction []
[2024.05.03-14.15.57:496][581]UATHelper: Packaging (Windows): LogWindows: Error:
[2024.05.03-14.15.57:496][581]UATHelper: Packaging (Windows): LogWindows: Error: end: stack for UAT
[2024.05.03-14.15.57:540][581]UATHelper: Packaging (Windows): Took 293,11s to run UnrealEditor-Cmd.exe, ExitCode=3
[2024.05.03-14.15.57:646][581]UATHelper: Packaging (Windows): Cook failed.