[COMPILE ERROR] - Stack overflow - code c00000fd

I’m getting an unexpected and project ending compile error when trying to compile all my Blueprint Classes. These files have not been changed, they were successfully built and packaged less than 24 hours ago.

This is all the information I have… please help!

MachineId:9490C48749D7E2C99E3CA4B1ADF60F20
EpicAccountId:

Stack overflow - code c00000fd (first/second chance not available)

UE4Editor_CoreUObject!UObject::Serialize() [d:\build++ue4+release-4.12+compile\sync\engine\source\runtime\coreuobject\private\uobject\obj.cpp:892]
UE4Editor_CoreUObject!UField::Serialize() [d:\build++ue4+release-4.12+compile\sync\engine\source\runtime\coreuobject\private\uobject\class.cpp:147]
UE4Editor_CoreUObject!UProperty::Serialize() [d:\build++ue4+release-4.12+compile\sync\engine\source\runtime\coreuobject\private\uobject\property.cpp:337]
UE4Editor_CoreUObject!FArchiveReplaceObjectRefBase::SerializeObject() [d:\build++ue4+release-4.12+compile\sync\engine\source\runtime\coreuobject\private\serialization\archiveuobject.cpp:198]
UE4Editor_UnrealEd!FArchiveReplaceObjectRef<UObject>::operator<<() [d:\build++ue4+release-4.12+compile\sync\engine\source\runtime\coreuobject\public\serialization\archiveuobject.h:1155]
UE4Editor_CoreUObject!UField::Serialize() [d:\build++ue4+release-4.12+compile\sync\engine\source\runtime\coreuobject\private\uobject\class.cpp:148]
UE4Editor_CoreUObject!UProperty::Serialize() [d:\build++ue4+release-4.12+compile\sync\engine\source\runtime\coreuobject\private\uobject\property.cpp:337]
UE4Editor_CoreUObject!FArchiveReplaceObjectRefBase::SerializeObject() [d:\build++ue4+release-4.12+compile\sync\engine\source\runtime\coreuobject\private\serialization\archiveuobject.cpp:198]
UE4Editor_UnrealEd!FArchiveReplaceObjectRef<UObject>::operator<<() [d:\build++ue4+release-4.12+compile\sync\engine\source\runtime\coreuobject\public\serialization\archiveuobject.h:1155]
UE4Editor_CoreUObject!UField::Serialize() [d:\build++ue4+release-4.12+compile\sync\engine\source\runtime\coreuobject\private\uobject\class.cpp:148]
UE4Editor_CoreUObject!UProperty::Serialize() [d:\build++ue4+release-4.12+compile\sync\engine\source\runtime\coreuobject\private\uobject\property.cpp:337]
UE4Editor_CoreUObject!FArchiveReplaceObjectRefBase::SerializeObject() [d:\build++ue4+release-4.12+compile\sync\engine\source\runtime\coreuobject\private\serialization\archiveuobject.cpp:198]
UE4Editor_UnrealEd!FArchiveReplaceObjectRef<UObject>::operator<<() [d:\build++ue4+release-4.12+compile\sync\engine\source\runtime\coreuobject\public\serialization\archiveuobject.h:1155]
UE4Editor_CoreUObject!UField::Serialize() [d:\build++ue4+release-4.12+compile\sync\engine\source\runtime\coreuobject\private\uobject\class.cpp:148]
UE4Editor_CoreUObject!UProperty::Serialize() [d:\build++ue4+release-4.12+compile\sync\engine\source\runtime\coreuobject\private\uobject\property.cpp:337]
UE4Editor_CoreUObject!FArchiveReplaceObjectRefBase::SerializeObject() [d:\build++ue4+release-4.12+compile\sync\engine\source\runtime\coreuobject\private\serialization\archiveuobject.cpp:198]
UE4Editor_UnrealEd!FArchiveReplaceObjectRef<UObject>::operator<<() [d:\build++ue4+release-4.12+compile\sync\engine\source\runtime\coreuobject\public\serialization\archiveuobject.h:1155]
UE4Editor_CoreUObject!UField::Serialize() [d:\build++ue4+release-4.12+compile\sync\engine\source\runtime\coreuobject\private\uobject\class.cpp:148]…

I can’t really say what’s up with that. You might want to check out the LOG files of your Project and add them. Please use the [spoiler] - Tag, so it’s not spamming the whole post.

Also, if you don’t use it yet, please consider using Source Control. Always, even for local projects. The ability to go back to a working state of your project is lifesaving.

Possible Cause / Solution

This keeps on coming up, and it seems to be related to passing values to other Blueprints through Custom Events and the values are really only defined after the program is running.

I’ve rigged a system to communicate from the Level Blueprint back to the Widget Blueprint and it seems to be a root of the issue.

The only noted warnings are basically…

"Info No value will be returned by reference. Parameter ‘variable’. Node: ‘checkSwitchnode’ "

However, I’ve managed a work around, where I go to the Widget Blueprint, disable the connection to the node, then I can go to the other Blueprints and compile them - then reconnecting the node that seems to be causing the error and compiling that blueprint.

Isn’t pretty, but it seems to get around the problem and the project will compile, build and package again.