Crash: "Sub-level assembly attempted inside plot of already removed sub-level" during Tree Physics + Aeronautics interaction

[MyraZaWitch]

Context
Summary
Server crashed with a RuntimeException from Sable's SubLevelAssemblyHelper.assembleBlocks
while a tree was being cut/falling. The exception message was: "Sub-level assembly attempted inside plot of already removed sub-level".

What we were doing
We were cutting down trees to harvest wood for airship fuel while parked at/near our
airship. The crash happened right after another tree fell nearby. On rejoining, the
airship was completely gone. So can delete current player made physics objects as well as any trees.

Relevant stack trace
java.lang.RuntimeException: Sub-level assembly attempted inside plot of already removed sub-level
at dev.ryanhcode.sable.api.SubLevelAssemblyHelper.assembleBlocks(SubLevelAssemblyHelper.java:85)
[mixins: aeronautics.mixins.json:balloon.SubLevelAssemblyHelperMixin from mod aeronautics,
treephysics.mixins.json:tree_splitting.SubLevelAssemblyHelperMixin from mod treephysics]
at dev.ryanhcode.sable.sublevel.plot.heat.SubLevelHeatMapManager.split(SubLevelHeatMapManager.java:242)
at dev.ryanhcode.sable.sublevel.plot.heat.SubLevelHeatMapManager.step(SubLevelHeatMapManager.java:118)
at dev.ryanhcode.sable.sublevel.plot.heat.SubLevelHeatMapManager.tick(SubLevelHeatMapManager.java:85)
at dev.ryanhcode.sable.sublevel.ServerSubLevel.tick(ServerSubLevel.java:235)
at dev.ryanhcode.sable.api.sublevel.SubLevelContainer.tick(SubLevelContainer.java:144)
at dev.ryanhcode.sable.api.sublevel.ServerSubLevelContainer.tick(ServerSubLevelContainer.java:90)

Impact
The airship and its full contents were completely lost on restart.

Versions
Sable: 2.0.3
Sable Companion: 1.6.0
Create Aeronautics: 1.3.0
Tree Physics: 2.2
Minecraft/NeoForge: 1.21.1
Full crash report attached.

Crash Report
crash-2026-07-10_03.25.50-server.txt
crash-2026-07-10_02.39.21-server.txt