Error when packaging

Ok, after endless hours of searching i have found out that the file was corrupted. Case closed

Hi! I encountered this issue today, and fixed it about 5 minutes ago, so my solution is fresh and will probably work for everyone. Although for those who do not have coding knowledge, I feel sorry, because I don't see any other way to properly track it down without debugger attached. So:

1. Run editor with debugger attached.

2. Enter the game - above error occurs, it will point you to the SoftObjectPath.cpp, but there is no info, so go to the callstack, and search for call in the file BlueprintEditorUtils.cpp. This function there will have FProperty as input, if you hover over it with debugger attached, it will show you EXACTLY which variable is causing the issue. Write its name down.

3. Go even deeper into the callstack down to the KismetCompiler.cpp. It must have gone through the function PropagateValuesToCDO. This method has UObject* InNewCDO as parameter, hover over it and write down the name of that variable.

4. Restart UE editor, find that asset, and that specific variable. Renaming won't work. I found that removing that variable completely, and adding brand new one WITH DIFFERENT NAME and manually replacing references missing after old one is removed fixes that error! Voila :)

It's possible to fix that without compiler, but UE callstack doesn't give you any info about what asset and variable this is all about. So tracking down which asset causes that might take much longer.

I had the same error. In my case it was missing calling "super" methods in overrided members of component.

 void USomeComponent::TickComponent(float DeltaTime, ELevelTick TickType,
     FActorComponentTickFunction* ThisTickFunction)
 {
     Super::TickComponent(DeltaTime, TickType, ThisTickFunction); // should be present
 }
 
 void USomeComponent::BeginPlay()
 {
     Super::BeginPlay(); // should be present
 }
 
 void USomeComponent::EndPlay(const EEndPlayReason::Type EndPlayReason)
 {
     Super::EndPlay(EndPlayReason); // should be present
 }

Adding these lines solved my problem.

In blueprints I had a similar error message with the soft object path, but mine was saying:

 Error: Ensure condition failed: !FPackageName::IsShortPackageName(Path)
 [File:D:/Build/++UE4/Sync/Engine/Source/Runtime/CoreUObject/Private/UObject/SoftObjectPath.cpp] [Line: 79]
 Error: Cannot create SoftObjectPath with short package name 'NoneNone'! You must pass in fully qualified package names

Then I made a backup of my project and deleted every blueprint one by one to find out which one was causing the problem. Once I found out which one it was, I started deleting parts of the code until I pinpointed my problem.

The issue got caused when I duplicated an actor reference variable and then changed it to another actor. So, I deleted that variable and created it from scratch and the problem was solved.

I'm not sure why that would happen because no error was given and it runs fine in the editor. Anyways, I thought I would share that just incase someone has a similar issue.