Quick answer: Godot 4 RigidBody3D's collision_layer warning when set above 31? Bitmask is 32 bits; bit 32+ is invalid - use bits 1-32.
Custom layer 'projectiles' assigned bit 33; warning floods console.
Use bits 1-32
Project Settings > Layer Names. Map names to bits 1-32.
Or use multiple bodies
If you need >32 layers, split into multiple physics worlds. Heavier; flexible.
Audit layer assignments
Each layer's bit. Above 32 = bug source.
“Collision layers are 32-bit. The limit is hardware.”
If you have many layer types, audit the assignment. Reuse where possible; split worlds only for genuine independence.