Hi, Same problem but I fix that. In my case problem was with “Placement” in Static Mesh Foliage, you can select on what Landscape Layers can spawn foliage. If you have different layers on landscape you can set to spawn ex: rocks on rock paint, plants, trees on dirt or grass paint etc. Problem was when I created new landscape I try to use same procedural foliage spawner that was maked for old one, after I removed all Inclusion Landscape Layers in Static Mesh Foliage all worked.