As you can see in the video, raycasts start and stop working (the terrain raycast is a special raycast from ULTIMATE TERRAINS, no physical raycast) I tried to make a reproduceable example, but I couldn't - if I generate a simple mesh (plane) in another scene, everything works great. But in the ULTIMATE TERRAINS scene, even simple colliders like the cube in the video won't get detected by raycasts. It's not a layer problem, because everything I do is uncheck the enabled toggle on the BoxCollider, re-check it and everything works for like 1 second. Is this a performance problem? Are there too many Mesh Colliders, so the whole Physic-Raycast System breaks?