How to tell which file causes `Cook content` to fail

Is there a way to see which file is causing the cooking process to fail? I’m using Unreal Engine 5.4.4 from Epic Launcher and not from source code.

When I run Windows / Cook Content the process fails with the following error. It is a new project that I was testing some stuff from “Paragon”, and I managed to track the error to TwinBlast. I was getting error Array.h] [Line: 758] when I was opening the included map as well, so I removed it using Explorer as I couldn’t do it in Editor as it was crashing even when trying to remove it.

UATHelper: Cooking (Windows): LogWindows: Error: appError called: Assertion failed: (Index >= 0) & (Index < ArrayNum) [File:D:\build\++UE5\Sync\Engine\Source\Runtime\Core\Public\Containers\Array.h] [Line: 758]
UATHelper: Cooking (Windows): Array index out of bounds: 61314 into an array of size 54111
PackagingResults: Error: appError called: Assertion failed: (Index >= 0) & (Index < ArrayNum) [File:D:\build\++UE5\Sync\Engine\Source\Runtime\Core\Public\Containers\Array.h] [Line: 758]
UATHelper: Cooking (Windows): LogWindows: Error: begin: stack for UAT
UATHelper: Cooking (Windows): LogWindows: Error: === Critical error: ===
UATHelper: Cooking (Windows): LogWindows: Error:
UATHelper: Cooking (Windows): LogWindows: Error: Assertion failed: (Index >= 0) & (Index < ArrayNum) [File:D:\build\++UE5\Sync\Engine\Source\Runtime\Core\Public\Containers\Array.h] [Line: 758]
UATHelper: Cooking (Windows): LogWindows: Error: Array index out of bounds: 61314 into an array of size 54111
UATHelper: Cooking (Windows): LogWindows: Error:
UATHelper: Cooking (Windows): LogWindows: Error:
UATHelper: Cooking (Windows): LogWindows: Error: [Callstack] 0x00007ffb6d210ec5 UnrealEditor-Engine.dll!UnknownFunction []
UATHelper: Cooking (Windows): LogWindows: Error: [Callstack] 0x00007ffb6d0fe1e8 UnrealEditor-Engine.dll!UnknownFunction []
UATHelper: Cooking (Windows): LogWindows: Error: [Callstack] 0x00007ffb6d2283d9 UnrealEditor-Engine.dll!UnknownFunction []
UATHelper: Cooking (Windows): LogWindows: Error: [Callstack] 0x00007ffb6d148da1 UnrealEditor-Engine.dll!UnknownFunction []
UATHelper: Cooking (Windows): LogWindows: Error: [Callstack] 0x00007ffb6a8523af UnrealEditor-CoreUObject.dll!UnknownFunction []
UATHelper: Cooking (Windows): LogWindows: Error: [Callstack] 0x00007ffb6a86dbd3 UnrealEditor-CoreUObject.dll!UnknownFunction []
UATHelper: Cooking (Windows): LogWindows: Error: [Callstack] 0x00007ffb6a85205b UnrealEditor-CoreUObject.dll!UnknownFunction []
UATHelper: Cooking (Windows): LogWindows: Error: [Callstack] 0x00007ffb6aa28523 UnrealEditor-CoreUObject.dll!UnknownFunction []
UATHelper: Cooking (Windows): LogWindows: Error: [Callstack] 0x00007ffb6aa0ea08 UnrealEditor-CoreUObject.dll!UnknownFunction []
UATHelper: Cooking (Windows): LogWindows: Error: [Callstack] 0x00007ffb6aa3c9a0 UnrealEditor-CoreUObject.dll!UnknownFunction []
UATHelper: Cooking (Windows): LogWindows: Error: [Callstack] 0x00007ffb6aa3accd UnrealEditor-CoreUObject.dll!UnknownFunction []
UATHelper: Cooking (Windows): LogWindows: Error: [Callstack] 0x00007ffb6aa3b2c0 UnrealEditor-CoreUObject.dll!UnknownFunction []
UATHelper: Cooking (Windows): LogWindows: Error: [Callstack] 0x00007ffb67b1ff61 UnrealEditor-UnrealEd.dll!UnknownFunction []
UATHelper: Cooking (Windows): LogWindows: Error: [Callstack] 0x00007ffb67b2020c UnrealEditor-UnrealEd.dll!UnknownFunction []
UATHelper: Cooking (Windows): LogWindows: Error: [Callstack] 0x00007ffb67b33aef UnrealEditor-UnrealEd.dll!UnknownFunction []
PackagingResults: Error: begin: stack for UAT
UATHelper: Cooking (Windows): LogWindows: Error: [Callstack] 0x00007ffb67b5f271 UnrealEditor-UnrealEd.dll!UnknownFunction []
UATHelper: Cooking (Windows): LogWindows: Error: [Callstack] 0x00007ffb67b5e704 UnrealEditor-UnrealEd.dll!UnknownFunction []
UATHelper: Cooking (Windows): LogWindows: Error: [Callstack] 0x00007ffb6783dd50 UnrealEditor-UnrealEd.dll!UnknownFunction []
PackagingResults: Error: === Critical error: ===
UATHelper: Cooking (Windows): LogWindows: Error: [Callstack] 0x00007ffb677ff6fd UnrealEditor-UnrealEd.dll!UnknownFunction []
UATHelper: Cooking (Windows): LogWindows: Error: [Callstack] 0x00007ffb6781aeb0 UnrealEditor-UnrealEd.dll!UnknownFunction []
UATHelper: Cooking (Windows): LogWindows: Error: [Callstack] 0x00007ff7b8ce80dd UnrealEditor-Cmd.exe!UnknownFunction []
PackagingResults: Error: Assertion failed: (Index >= 0) & (Index < ArrayNum) [File:D:\build\++UE5\Sync\Engine\Source\Runtime\Core\Public\Containers\Array.h] [Line: 758]
UATHelper: Cooking (Windows): LogWindows: Error: [Callstack] 0x00007ff7b8cde146 UnrealEditor-Cmd.exe!UnknownFunction []
UATHelper: Cooking (Windows): LogWindows: Error: [Callstack] 0x00007ff7b8cde42a UnrealEditor-Cmd.exe!UnknownFunction []
PackagingResults: Error: Array index out of bounds: 61314 into an array of size 54111
UATHelper: Cooking (Windows): LogWindows: Error: [Callstack] 0x00007ff7b8ce18a4 UnrealEditor-Cmd.exe!UnknownFunction []
UATHelper: Cooking (Windows): LogWindows: Error: [Callstack] 0x00007ff7b8cf70c4 UnrealEditor-Cmd.exe!UnknownFunction []
PackagingResults: Error: [Callstack] 0x00007ffb6d210ec5 UnrealEditor-Engine.dll!UnknownFunction []
UATHelper: Cooking (Windows): LogWindows: Error: [Callstack] 0x00007ff7b8cf96e6 UnrealEditor-Cmd.exe!UnknownFunction []
PackagingResults: Error: [Callstack] 0x00007ffb6d0fe1e8 UnrealEditor-Engine.dll!UnknownFunction []
UATHelper: Cooking (Windows): LogWindows: Error: [Callstack] 0x00007ffbfc46257d KERNEL32.DLL!UnknownFunction []
UATHelper: Cooking (Windows): LogWindows: Error:
PackagingResults: Error: [Callstack] 0x00007ffb6d2283d9 UnrealEditor-Engine.dll!UnknownFunction []
UATHelper: Cooking (Windows): LogWindows: Error: end: stack for UAT
PackagingResults: Error: [Callstack] 0x00007ffb6d148da1 UnrealEditor-Engine.dll!UnknownFunction []
PackagingResults: Error: [Callstack] 0x00007ffb6a8523af UnrealEditor-CoreUObject.dll!UnknownFunction []
PackagingResults: Error: [Callstack] 0x00007ffb6a86dbd3 UnrealEditor-CoreUObject.dll!UnknownFunction []
PackagingResults: Error: [Callstack] 0x00007ffb6a85205b UnrealEditor-CoreUObject.dll!UnknownFunction []
PackagingResults: Error: [Callstack] 0x00007ffb6aa28523 UnrealEditor-CoreUObject.dll!UnknownFunction []
PackagingResults: Error: [Callstack] 0x00007ffb6aa0ea08 UnrealEditor-CoreUObject.dll!UnknownFunction []
PackagingResults: Error: [Callstack] 0x00007ffb6aa3c9a0 UnrealEditor-CoreUObject.dll!UnknownFunction []
PackagingResults: Error: [Callstack] 0x00007ffb6aa3accd UnrealEditor-CoreUObject.dll!UnknownFunction []
PackagingResults: Error: [Callstack] 0x00007ffb6aa3b2c0 UnrealEditor-CoreUObject.dll!UnknownFunction []
PackagingResults: Error: [Callstack] 0x00007ffb67b1ff61 UnrealEditor-UnrealEd.dll!UnknownFunction []
PackagingResults: Error: [Callstack] 0x00007ffb67b2020c UnrealEditor-UnrealEd.dll!UnknownFunction []
PackagingResults: Error: [Callstack] 0x00007ffb67b33aef UnrealEditor-UnrealEd.dll!UnknownFunction []
PackagingResults: Error: [Callstack] 0x00007ffb67b5f271 UnrealEditor-UnrealEd.dll!UnknownFunction []
PackagingResults: Error: [Callstack] 0x00007ffb67b5e704 UnrealEditor-UnrealEd.dll!UnknownFunction []
PackagingResults: Error: [Callstack] 0x00007ffb6783dd50 UnrealEditor-UnrealEd.dll!UnknownFunction []
PackagingResults: Error: [Callstack] 0x00007ffb677ff6fd UnrealEditor-UnrealEd.dll!UnknownFunction []
PackagingResults: Error: [Callstack] 0x00007ffb6781aeb0 UnrealEditor-UnrealEd.dll!UnknownFunction []
PackagingResults: Error: [Callstack] 0x00007ff7b8ce80dd UnrealEditor-Cmd.exe!UnknownFunction []
PackagingResults: Error: [Callstack] 0x00007ff7b8cde146 UnrealEditor-Cmd.exe!UnknownFunction []
PackagingResults: Error: [Callstack] 0x00007ff7b8cde42a UnrealEditor-Cmd.exe!UnknownFunction []
PackagingResults: Error: [Callstack] 0x00007ff7b8ce18a4 UnrealEditor-Cmd.exe!UnknownFunction []
PackagingResults: Error: [Callstack] 0x00007ff7b8cf70c4 UnrealEditor-Cmd.exe!UnknownFunction []
PackagingResults: Error: [Callstack] 0x00007ff7b8cf96e6 UnrealEditor-Cmd.exe!UnknownFunction []
PackagingResults: Error: [Callstack] 0x00007ffbfc46257d KERNEL32.DLL!UnknownFunction []
PackagingResults: Error: end: stack for UAT

I started opening all the files in hope that it will do the same as it did with the map, meaning it will crash when I open it. And well it did.

The problem was with Skeletal Mesh Summer Time. I didn’t thought to check the skeletal meshes, as they were working just fine in a test project using 5.3 what my main project is using, and I tested it just now (in a new 5.3 project), and that mesh is working fine in 5.3 but it crashes the engine in 5.4 with that array line 758 error.

So yeah, I think I will skip the upgrade to 5.4 and wait for 5.5 as I don’t want other stuff to break.