Unreal Engine 4 | project crash

I think

  • I was creating a new variable in a structure then I pressed the save Button
  • or I was working on a Blueprint class then I pressed the Compile Button

(while opening like 5 others)&(I don’t use VisualStudio at all)(it contains lots of packs)

then the engine crashed
My Unreal Engine Version is 4.27

the crash [Assertion failed: Tag.Size == Loaded [File:D:/Build/++UE4/Sync/Engine/Source/Runtime/CoreUObject/Private/UObject/Class.cpp] [Line: 1499]]

Crash Log:
End_Live_Through_It.log (173.6 KB)

I tried to

  1. open it again, but it keeps giving me that crash every time
  2. Verify the Engine, version but still didn’t work
  3. solutions on {google, youtube, Unreal HUB & discord}
  4. generate a VisualStudio project, (didn’t work because I have to create a C++ class while the project is open)

nothing worked, I hope you can help me

Hey there @Hamo_Dark_Knight! This is a weird one. Which version of UE4 were you using? I’m guessing 4.27 but don’t want to assume. That specific line is crashing due to a check on the tag. Which seems descriptive, but in reality it isn’t. Errors like this on stable engine versions are often down to interference with a plugin or accidentally messing with engine content in project. This only occurs during BP compilation though?

I think I was adding a new variable in a structure then I pressed save Button
or I was working on a Blueprint class then I pressed Compile Button
My Unreal Engine Version is 4.27

Even in context the error doesn’t make much sense, looking over the source I’m not sure what triggered it. It could be whatever’s stored tag side on the BP you’re editing is corrupted. Does this occur with any other BPs or just one that you’d been working on?

I was having a lot of crashes like this when I compile, save changes or when deleting a file, but this crash made me unable to open the project at all, It’s now fixed after I removed the BP file, I think because I changed a Structure and It’s already used in that BP, but It’s also Used in a lot of other BPs, I really don’t know why precisely that Bp, I was working as usual without any other 3d party apps, as long as I send the crash to Unreal Support from the Button (Send and restart) I don’t see any Email about the bug anymore, I think it maybe doesn’t arrive them, thank you for your help!

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No worries, glad you resolved it! The bug reports go directly to the ticketing system, so generally you don’t get much notification unless someone reaches out for more information. Thanks for submitting however!