Bug Exception during SubScene import: T must already be filtered by ComponentSystemBase or ISystem

Unity 2022.2.0b14 / com.unity.entities@1.0.0-exp.12

What this message wants me to do, exactly?

Here is the source code that throws this exception:

Code (CSharp):

1. // Only derivatives of ComponentSystemBase and structs implementing ISystem are systems
2. if (!type.IsSubclassOf(typeof(ComponentSystemBase)) && !typeof(ISystem).IsAssignableFrom(type))
3.     throw new System.ArgumentException($"{type} must already be filtered by ComponentSystemBase or ISystem");

What is baffling here is that this TYPE_NAME in my case are seemingly random types like

EHex

enum or

MyComponentAuthoring+<>c__DisplayClass11_0

codegen piece.

 

Same issue, in my case the component has nothing to do with ECS. Errors only pops up when unloading the subscene from the editor view though.

 

I've seen this happen a number of times after I make some class hierarchy changes / additions in user code, mostly when adding / removing complete C# files from within an IDE, then coming back to Unity and triggering baking through Play Mode or just opening the relevant scene. I don't know of a surefire repro for this, though. To my memory, nothing was amiss just changing method implementations or otherwise changing things within types. I generally seem to be able to get around this by adding / removing / refactoring things while Unity is closed. When the problems do crop up, you can either reimport everything / delete Library/ (not great, of course) or try clearing Entities caches (in this case, also annoyingly, if it's still bugged after reloading the Editor, you go and delete the generated cache version info in Assets/).

 

Seems like reloading works for me. As mentioned before triggers when class hierarchy changes. Unity 2022.2.0b16 / entities 1.0.0-exp.12

 

I also encounter this regularly, especially when renaming classes/structs or when moving classes/structs to a new namespace or assembly. The larger the change the more likely it is to happen.

I have to delete the Library folder, the GlobalEntitiesDependencies folder & SceneDependencyCache folder.
Just clearing the Entity Cache does not fix it.

Like you said, the errors don't make any sense.
It could be a bug with the TypeManager and the AssetImporter.