What code should be avoided from an object's CD0?

[BrUnO_XaVIeR]

If you want to work with CDO and constructors you should first learn about Object Flags, such as RF_ClassDefaultObject, and understand why they exist and how they can be used.

Some common mistakes with constructors in Unreal can brick your project to a point where it will never open in Editor again.

I had to spend long nights looking inside engine source code until I understood what Unreal is really doing with constructors…

Explaining components initialization functions flow..

When you create a BP class you usually get: Archetype Class - this is a “skeleton” of your C++ Class + Generated Code (Unreal’s Reflection System) Default Object - this is the “generated class” the engine creates every time you run it, there’s always a “Class Default Object” or “CDO”; This is where you’ll see “GEN_VARIABLE” thingies. Instanced Object - this will “spawn” in game world and copy default values from CDO once created (expose on spawn stuff, etc). So the code you’ve created there …