Blueprint nativization produces a crashing build when adding child actor components with a class already set

If you have your project set for inclusive blueprint nativization and are using the “Add Child Actor Component” blueprint node AND that node has a child actor class set, you will be able to package a project successfully but the resulting project will hard crash on launch with an error. Kind of like this one:

[2017.06.13-21.33.46:135][  0]LogWindows:Error: Fatal error: [File:D:\Build\++UE4+Release-4.16+Compile\Sync\Engine\Source\Runtime\CoreUObject\Private\Serialization\AsyncLoading.cpp] [Line: 2781] 
[2017.06.13-21.33.46:135][  0]LogWindows:Error: Missing import of (/Game/NewMap): NODE_AddChildActorComponent-0_ChildActorClass_C_CAT in Package /Game/ActorClass was not found, but the package exists.

Adding a child actor component with no class set and then setting the class after with the “Set Child Actor Class” node does work. This makes me think that the issue may be related to the project not understanding that the class is in use and skipping adding it to the project. I would be happy to send someone my test project if it would help.

This issue has been fixed for the next release, thanks for the report!

As a workaround until then, you will need to move the ChildActorComponent into the Components tree in the Blueprint editor (i.e. instead of using an AddChildActorComponent node), and that should allow the packaged build to launch.

Hope this helps!

Awesome, thanks!

Hello blobdole,

Thank you for reporting this issue. I’ve entered a bug report for it which you can find here: UE-46054. You can use that link to track the issue’s progress and any updates it may receive.

Have a nice day!

I am on 4.21 and I’m experiencing this again.