Why do my prefabs not have an Asset Preview?

I’ve been working on a Level Editor Tool for a game I’m working on and one of the things I wanted to do was make a list of prefabs for a level palette the developer can select from to paint into the scene. To do that I was going to use AssetPreview.GetAssetPreview(); however, for some reason some of my prefabs are not creating Asset Previews.


The prefabs are literally just a cube with a Standard Surface Shader with the Albedo color as Brown/Green respectively.


I have already attempted to Rescale the Prefab list in the Project tab, Reimport the prefabs, and recreate them from scratch but they have not updated the Asset Preview. Any ideas on how I can resolve this issue?

I ended up figuring it out. Using a Custom Editor Script for GameObjects caused the issue.


Changed it to Transform instead.