https://docs.unity3d.com/2018.4/Documentation/Manual/PartSysShapeModule.html What exactly means "If you assign them in the Editor, Unity handles this for you."? What handles the Editor? The Editor doesn't turn on "Read/Write Enabled" on the mesh Import Settings, I checked this. Or will the Editor enable "Read/Write Enabled" internally, but fail to do so when building a Player? I'm wondering if I must turn on "Read/Write Enabled" on all meshes that are used for ParticleSystems.