Project wont open all of the sudden - Assertion failed: Export.ScriptSerializationStartOffset

Development Platform & Builds
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1

I need help! I’ve been working on this project for a few months (although there are elements of earlier projects) – there are some gameplay systems but I’ve been mostly concentrating on getting a world partition-enabled level set up that looks good and runs at least ok. I had a harddrive error maybe a week ago, but everything was working fine except for a few files. After working all night last night, and shutting down the editor without a problem, it all of the sudden has started crashing on launch.

Last night I was doing asset management. I created a few new materials, modified the default materials on a few static meshes, placed some assets in a staging/overview level, and added a number of assets to collections. I believe that’s it. Everything on my computer has been updated as of this morning. The project is fairly massive, and ironically I was trying to cut out unneeded assets, but again, it opened fine just last night.

So, how do I deal with this? If there is a particular corrupted file, how do I find it? If it’s my harddrive, could I potentially move the project to a different harddrive and try to open it, or is that dangerous? How can I avoid this in the future?

Can anyone tell me more about script serialization and deserialization?

Here’s the full error message:

Assertion failed: Export.ScriptSerializationStartOffset == (Tell() - Export.SerialOffset) [File:D:\build++UE5\Sync\Engine\Source\Runtime\CoreUObject\Private\UObject\LinkerLoad.cpp] [Line: 6295] Serialized script property start offset does not match offset during deserialization

UnrealEditor_CoreUObject
UnrealEditor_CoreUObject
UnrealEditor_CoreUObject
UnrealEditor_Engine
UnrealEditor_Engine
UnrealEditor_InterchangeEngine
UnrealEditor_CoreUObject
UnrealEditor_CoreUObject
UnrealEditor_CoreUObject
UnrealEditor_CoreUObject
UnrealEditor_CoreUObject
UnrealEditor_CoreUObject
UnrealEditor_UnrealEd
UnrealEditor_UnrealEd
UnrealEditor_UnrealEd
UnrealEditor_Core
UnrealEditor_Engine
UnrealEditor_UnrealEd
UnrealEditor_UnrealEd
UnrealEditor_UnrealEd
UnrealEditor_UnrealEd
UnrealEditor_UnrealEd
UnrealEditor
UnrealEditor
UnrealEditor
UnrealEditor
UnrealEditor
kernel32
ntdll

…
Any help would be much appreciated!

2

Hey @Sleazy_Mudkip!

Try running a verification scan on your installation of UE!

Pretty sure this is engine files, not project files. :slight_smile:
Hope that helps!

1 Like
3

By verification scan, do you mean through command line?
I’m running chkdsk right now and it’s found a few things in my project already. (Looks like it’s gonna take 3 hours though)
thanks!

4

Chkdsk is also a good idea!

I meant this though:

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image366×331 37.4 KB

5

Thanks, I forgot that was there. I canceled the chkdsk to see if it would work, but no luck. I’ll have to start it running again but it was worth a shot. I also tried deleting the derived data cache (I’d already deleted the saved and intermediate folders except for Collections.)

Worth noting that other projects boot up fine. I’m so frustrated with myself for not backing up the project for months. Fingers crossed I can fix it