Unknown cook failure from animsequence.cpp

Here is the error I got:
UATHelper: Packaging (Windows (64-bit)): LogInit: Display: Warning/Error Summary (Unique only)
UATHelper: Packaging (Windows (64-bit)): LogInit: Display: -----------------------------------
UATHelper: Packaging (Windows (64-bit)): LogInit: Display: LogOutputDevice: Error: begin: stack for UAT
UATHelper: Packaging (Windows (64-bit)): LogInit: Display: LogOutputDevice: Error: === Handled ensure: ===
UATHelper: Packaging (Windows (64-bit)): LogInit: Display: LogOutputDevice: Error:
UATHelper: Packaging (Windows (64-bit)): LogInit: Display: LogOutputDevice: Error: Ensure condition failed: !DoesContainTransformCurves() || (RawAnimationData.Num()==0 || SourceRawAnimationData.Num() != 0) [File:D:\Build++UE4+Release-4.19+Compile\Sync\Engine\Source\Runtime\Engine\Private\Animation\AnimSequence.cpp] [Line: 371]
UATHelper: Packaging (Windows (64-bit)): LogInit: Display: LogOutputDevice: Error: Stack:
UATHelper: Packaging (Windows (64-bit)): LogInit: Display: LogOutputDevice: Error: [Callstack] 0x000000006A89BA76 UE4Editor-Core.dll!UnknownFunction []
UATHelper: Packaging (Windows (64-bit)): LogInit: Display: LogOutputDevice: Error: [Callstack] 0x000000006A5FAE3A UE4Editor-Core.dll!UnknownFunction []
UATHelper: Packaging (Windows (64-bit)): LogInit: Display: LogOutputDevice: Error: [Callstack] 0x000000006A60ECD6 UE4Editor-Core.dll!UnknownFunction []
UATHelper: Packaging (Windows (64-bit)): LogInit: Display: LogOutputDevice: Error: [Callstack] 0x0000000064EB513B UE4Editor-Engine.dll!UnknownFunction []
UATHelper: Packaging (Windows (64-bit)): LogInit: Display: LogOutputDevice: Error: [Callstack] 0x000000006A11B9E7 UE4Editor-CoreUObject.dll!UnknownFunction []
UATHelper: Packaging (Windows (64-bit)): LogInit: Display: LogOutputDevice: Error: [Callstack] 0x000000006A104140 UE4Editor-CoreUObject.dll!UnknownFunction []
UATHelper: Packaging (Windows (64-bit)): LogInit: Display: LogOutputDevice: Error: [Callstack] 0x0000000068255264 UE4Editor-UnrealEd.dll!UnknownFunction []
UATHelper: Packaging (Windows (64-bit)): LogInit: Display: LogOutputDevice: Error: [Callstack] 0x00000000680FEEEB UE4Editor-UnrealEd.dll!UnknownFunction []
UATHelper: Packaging (Windows (64-bit)): LogInit: Display: LogOutputDevice: Error: [Callstack] 0x000000006810022D UE4Editor-UnrealEd.dll!UnknownFunction []
UATHelper: Packaging (Windows (64-bit)): LogInit: Display: LogOutputDevice: Error: [Callstack] 0x000000006810BC59 UE4Editor-UnrealEd.dll!UnknownFunction []
UATHelper: Packaging (Windows (64-bit)): LogInit: Display: LogOutputDevice: Error: [Callstack] 0x0000000067FBA580 UE4Editor-UnrealEd.dll!UnknownFunction []
UATHelper: Packaging (Windows (64-bit)): LogInit: Display: LogOutputDevice: Error: [Callstack] 0x0000000067FE1CB0 UE4Editor-UnrealEd.dll!UnknownFunction []
UATHelper: Packaging (Windows (64-bit)): LogInit: Display: LogOutputDevice: Error: [Callstack] 0x00000000DE6AEB20 UE4Editor-Cmd.exe!UnknownFunction []
UATHelper: Packaging (Windows (64-bit)): LogInit: Display: LogOutputDevice: Error: [Callstack] 0x00000000DE6A69FA UE4Editor-Cmd.exe!UnknownFunction []
UATHelper: Packaging (Windows (64-bit)): LogInit: Display: LogOutputDevice: Error: [Callstack] 0x00000000DE6A6C4A UE4Editor-Cmd.exe!UnknownFunction []
UATHelper: Packaging (Windows (64-bit)): LogInit: Display: LogOutputDevice: Error: [Callstack] 0x00000000DE6B4149 UE4Editor-Cmd.exe!UnknownFunction []
UATHelper: Packaging (Windows (64-bit)): LogInit: Display: LogOutputDevice: Error: [Callstack] 0x00000000DE6B4F87 UE4Editor-Cmd.exe!UnknownFunction []
UATHelper: Packaging (Windows (64-bit)): LogInit: Display: LogOutputDevice: Error: [Callstack] 0x00000000BBA83034 KERNEL32.DLL!UnknownFunction []
UATHelper: Packaging (Windows (64-bit)): LogInit: Display: LogOutputDevice: Error: [Callstack] 0x00000000BD7F1431 ntdll.dll!UnknownFunction []
UATHelper: Packaging (Windows (64-bit)): LogInit: Display: LogOutputDevice: Error: end: stack for UAT
UATHelper: Packaging (Windows (64-bit)): LogInit: Display:
UATHelper: Packaging (Windows (64-bit)): LogInit: Display: Failure - 27 error(s), 0 warning(s)
UATHelper: Packaging (Windows (64-bit)): LogInit: Display:
UATHelper: Packaging (Windows (64-bit)):
UATHelper: Packaging (Windows (64-bit)): Execution of commandlet took: 58.15 seconds
UATHelper: Packaging (Windows (64-bit)): Took 72.1924922s to run UE4Editor-Cmd.exe, ExitCode=1
UATHelper: Packaging (Windows (64-bit)): ERROR: Cook failed.
UATHelper: Packaging (Windows (64-bit)): (see C:\Users\zevia\AppData\Roaming\Unreal Engine\AutomationTool\Logs\C+Program+Files+(x86)+UE_4.19\UAT_Log.txt for full exception trace)
UATHelper: Packaging (Windows (64-bit)): AutomationTool exiting with ExitCode=25 (Error_UnknownCookFailure)
UATHelper: Packaging (Windows (64-bit)): BUILD FAILED
PackagingResults: Error: Unknown Cook Failure
LogSlate: Window ‘Output Log’ being destroyed
LogSlate: Window ‘Output Log’ being destroyed
LogSlate: FSceneViewport::OnFocusLost() reason 0

I’m “glad” that everything works until I actually package something.
everytime I get these errors I have to ask about it, it never actually lets me know what I’m doing wrong

Had a similar Error: Unknown Cook Failure error around animsequence.cpp in Unreal 5.0.0 recently and just wanted to report what the solution was in case anyone else ever encounters the issue, since at the time I was troubleshooting it, I could not find any leads to similar problems online that checked all the right boxes.

It may not be the exact same problem, but if you encounter a cooking error revolving around animsequence.cpp with a red wall of “UnknownFunction” dominating the log, this might help to narrow the search a bit.

In my case, it was a single corrupt character animation sequence file that for some unknown reason, had an “Import Resample Framerate” of 0. Completely deleting the file, followed by a clean re-import and “Fix Up Redirectors in Folder” did the trick.

Similar to what Spacer789 experienced, the project worked perfectly fine with Play In Editor, but always resulted in a Cook failure as long as that animation sequence file existed, even when not actually referenced by an Animation Blueprint. Basically, its sheer existence alone caused the Cook to fail. It also did not trigger any specific issues with blueprint compiling or data validation in the Editor, and the UATHelper log during cooking never actually mentioned it by file name, which made it notably hard to pinpoint.