We do not allow prefabs that contain a mesh with LOD written in its name, but without an LOD element or more than 1 mesh attached. Please make sure that LODs are correctly set up in the prefab. Refer to the LODGroup Manual to set up your LODs. It says that on each of my nested prefabs and I cannot publish my asset, what am I supposed to do ? Exemple of prefab : [Prefab]ObjectA ObjectO [Prefab]ObjectE [Prefab][LOD Group]ObjectU Mesh_LOD0 Mesh_LOD1 Mesh_LOD2 ObjectA and ObjectE prefabs would appear as invalid by the validator. This person said their asset was accepted even with validation error but I tried it and mine got rejected.