System cannot be constructed as it does not inherit from ComponentSystemBase

Unity Engine
, , ,
1

Hi, getting this error on a system. I can delete all of the code to make it basically empty but it doesn’t prevent the error. Is this codegen related? The system seems to be running fine in play mode.

[Worker0] ArgumentException: ‘XXXSystem’ cannot be constructed as it does not inherit from ComponentSystemBase
Unity.Entities.TypeManager.ConstructSystem (System.Type systemType) (at Library/PackageCache/com.unity.entities@1.3.8/Unity.Entities/Types/TypeManagerSystems.cs:701)

2

This may be caused by corrupt cached files. Could you try deleting the project’s Library folder and reopening the project?

If the issue persists, please report this bug from within the Unity Editor by selecting Help → Report a Bug…

1 Like
3

Deleting the library folder didn’t work. I’ll try to repro it in an empty project.

4

In my case I was getting this error because I had a managed unity object field in an ISystem-based system struct.
Removing the field solved the problem.

public partial struct SelectionHandlingSystem : ISystem
{
    private Camera _mainCamera; // <- illegal!
    ...

I guess managed object fields are allowed in a SystemBase system?

5

No they’re not. If you’re using managed code use SystemBase - that’s basically the difference between them