diff --git a/src/AcDream.App/Rendering/GameWindow.cs b/src/AcDream.App/Rendering/GameWindow.cs
index 292c6b5..8e0fa7b 100644
--- a/src/AcDream.App/Rendering/GameWindow.cs
+++ b/src/AcDream.App/Rendering/GameWindow.cs
@@ -3766,11 +3766,22 @@ public sealed class GameWindow : IDisposable
     /// </summary>
     private void OnLiveStateUpdated(AcDream.Core.Net.Messages.SetState.Parsed parsed)
     {
-        _physicsEngine.ShadowObjects.UpdatePhysicsState(parsed.Guid, parsed.PhysicsState);
+        // L.2g slice 1c (2026-05-13): the server addresses entities by
+        // ServerGuid (parsed.Guid, e.g. 0x7A9B4015), but
+        // ShadowObjectRegistry's cell index is keyed by local entity.Id
+        // (e.g. 0x000F4245). Translate via _entitiesByServerGuid before
+        // mutating the registry — otherwise the lookup misses and the
+        // state flip silently no-ops, leaving doors blocked even though
+        // ACE flipped the ETHEREAL bit.
+        uint registryKey = parsed.Guid;
+        if (_entitiesByServerGuid.TryGetValue(parsed.Guid, out var entity))
+            registryKey = entity.Id;
+
+        _physicsEngine.ShadowObjects.UpdatePhysicsState(registryKey, parsed.PhysicsState);
 
         if (AcDream.Core.Physics.PhysicsDiagnostics.ProbeBuildingEnabled)
             Console.WriteLine(System.FormattableString.Invariant(
-                $"[setstate] guid=0x{parsed.Guid:X8} state=0x{parsed.PhysicsState:X8} instSeq={parsed.InstanceSequence} stateSeq={parsed.StateSequence}"));
+                $"[setstate] guid=0x{parsed.Guid:X8} entityId=0x{registryKey:X8} state=0x{parsed.PhysicsState:X8} instSeq={parsed.InstanceSequence} stateSeq={parsed.StateSequence}"));
     }
 
     private static bool IsRemoteLocomotion(uint motion)