What is meaning of "level instance is not using external actors"

Hello, I am migrating a traditional level to world-partition level. I converted the original level using the editor tool. Then I create LevelInstance Actor Blueprints and set their “Level” property as original sublevels; then I added the LevelInstance to the converted level. Everything seems work well. However, I got error messages “level instance is not using external actors”.

I don’t understand the meaning of these errors, nor know how to fix them. Could anyone help me about this please? Thanks in advance.

You can right clicked on the instanced level(s) in the content browser and choose called “add partitioned streaming support…” to fix the error.

What is it doing? I can’t see the level instance actor anymore when I go into PIE

Try to load it in the world partition panel.

Here’s the answer on Reddit.

In short enable OFPA for the normal map that you were using as an instance.

谢谢,我才发现是在Content里右键关卡才能找到这个选项。我一直在场景大纲里找,难怪找不到。