Crash with Create Big Cannons: "Body has been removed" when a CBC shell destroys an Aeronautics/Sable sub-level (1.21.1, NeoForge)

[Svinkimoideti]

Description
When a Create Big Cannons shell impacts and destroys a Sable sub-level (Create: Aeronautics structure), the game crashes with java.lang.RuntimeException: Body has been removed.
Environment

• Sable: 2.0.3+mc1.21.1 (latest)
• Create Big Cannons: 5.11.7+mc.1.21.1 (latest)
• Minecraft: 1.21.1, NeoForge: 21.1.248
• Singleplayer, Arch Linux x86_64
  Stack trace (abridged)
  java.lang.RuntimeException: Body has been removed
  at RapierPhysicsPipeline.assertBodyValid(RapierPhysicsPipeline.java:578)
  at RapierPhysicsPipeline.getLinearVelocity(RapierPhysicsPipeline.java:485)
  at RigidBodyHandle.getLinearVelocity(RigidBodyHandle.java:161)
  at ActiveSableCompanion.getVelocity(...)
  at EntitySubLevelUtil.wrapOperation$...$createbigcannons$kickEntity$mul(EntitySubLevelUtil.java:529)
  [mixin APP: createbigcannons.mixins.json:compat.sable.EntitySubLevelUtilMixin]
  at EntitySubLevelUtil.kickEntity(...)
  at ServerLevelPlot.kickAllEntities(ServerLevelPlot.java:279)
  at ServerSubLevel.deleteAllEntities(ServerSubLevel.java:407)
  at ServerSubLevelContainer.removeSubLevel(ServerSubLevelContainer.java:137)
  at SubLevelContainer.processSubLevelRemovals(...)
  It happens while Sable removes a sub-level: CBC's EntitySubLevelUtilMixin calls getVelocity() on a rigid body that was already removed from the physics world.
  Repro

1. Build an Aeronautics structure (sub-level).
2. Hit it with a Create Big Cannons shell so the structure is destroyed/removed.
3. Crash on sub-level removal.
   Notes

• Related: Sub-level unrecoverable after crash during autosave — index pointer persists but payload keeps changing on every save #1438 (same exception, different path — autosave).
• Full crash report attached.
  crash-2026-08-09_12.11.28-server.txt