# CollisionGroup that doesn't contact Default is un-raycastable

If a CollisionGroup doesn't collide with the Default Collision Group, it will fail all raycast checks no mattrer what property you set. This is a legacy bug that has become so widely relied on that it will never be fixed. Even the Mouse raycast will fail, making it impossible to select objects on that collisiongroup in studio.\
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<https://devforum.roblox.com/t/studio-selection-doesnt-work-if-collisiongroup-doesnt-collide-with-default-group/796320/17>