I am trying to use mesh for grass for my terrain. The LOD seem to be working when i test in in the scene, but when i try to use it as detail for “Paint Details” i get this message … What am i doing wrong ?

Terrain details are not rendered as GameObjects with Renderer components. They’re batch rendered from the terrain data. I suspect that the error message you’re getting is all there is to it. You just can’t use LOD Group components on something you’re using as a terrain detail object because the terrain rendering system doesn’t support them - which makes sense, because it works fundamentally differently.
So … how can i scatter grass that is not simply a texture but a mesh ? Can you do it trough the terrain system or i should find some other way ?
I think you can do it through the terrain system, you just need to not have a LOD Group in there. But I can’t give any detail as I’ve not used that system in quite some time.
I get the “render component is missing” message when i try a non LOD mesh/prefab.
The reason i had problems and meshes not appearing was because of the fbx export. Had to uncheck the “input connections” option when i was exporting stuff from maya, and that fixed it.
I am having this same issue but with purchased assets
Add your Gameobject inside the Tree tab and create a brush and paint.
Worked for me!
I still don’t understand why this has to be an error. If they are not actually rendered as gameobjects, why isn’t the component simply ignored as any other unrelated component?