PackagingResults: Error: Unknown Cook Failure

Recently, I’ve been working on a project, and it was running fine: no crashes or anything, until I try to package the game. Originally I had an ‘unknown packaging error’ but after looking at some forum posts and setting it to ‘shipping’ instead of ‘development’, it’s now just an unknown cooking error.

the end of the output log is below (it all starts off fine, then it runs into some errors, then this)

UATHelper: Packaging (Windows (64-bit)):   LogInit: Display:
UATHelper: Packaging (Windows (64-bit)):   LogInit: Display: Failure - 14 error(s), 40 warning(s)
UATHelper: Packaging (Windows (64-bit)):   LogInit: Display:
UATHelper: Packaging (Windows (64-bit)):   
UATHelper: Packaging (Windows (64-bit)):   Execution of commandlet took:  12.96 seconds
UATHelper: Packaging (Windows (64-bit)): Took 26.0516463s to run UE4Editor-Cmd.exe, ExitCode=1
UATHelper: Packaging (Windows (64-bit)): Cook failed. Deleting cooked data.
UATHelper: Packaging (Windows (64-bit)): ERROR: Cook failed.
UATHelper: Packaging (Windows (64-bit)):        (see C:\Users\User\AppData\Roaming\Unreal Engine\AutomationTool\Logs\D+UE4+UE_4.18\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: Took 0.018666 seconds to synchronously load lazily loaded font '../../../Engine/Content/Editor/Slate/Fonts/DroidSansMono.ttf' (77K)

I’m kind of a newbie to UE4, and I have no idea why it breaks in 4.19 or above, or why it runs into these issues. I hope this issue hasn’t been resolved thousands of times, and I’m just being really stupid :confused:

Game file download:

(Please note: the blueprints completely break for some unknown reason when loaded up in 4.19 or above.)

Some help would be appreciated :slight_smile:
Thanks