From 09614b74a63873e2f18e403b3c7d01030bf446c0 Mon Sep 17 00:00:00 2001
From: lap2ka <83134094+lap2ka@users.noreply.github.com>
Date: Wed, 20 May 2026 01:24:50 +0200
Subject: [PATCH 1/2] Prevent NPE for weightless contraptions

---
 .../AbstractContraptionEntityMixin.java             | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/neoforge/src/main/java/dev/ryanhcode/sable/neoforge/mixin/compatibility/create/contraptions/AbstractContraptionEntityMixin.java b/neoforge/src/main/java/dev/ryanhcode/sable/neoforge/mixin/compatibility/create/contraptions/AbstractContraptionEntityMixin.java
index a6661e82..46ca9001 100644
--- a/neoforge/src/main/java/dev/ryanhcode/sable/neoforge/mixin/compatibility/create/contraptions/AbstractContraptionEntityMixin.java
+++ b/neoforge/src/main/java/dev/ryanhcode/sable/neoforge/mixin/compatibility/create/contraptions/AbstractContraptionEntityMixin.java
@@ -99,7 +99,9 @@ public AbstractContraptionEntityMixin(final EntityType<?> arg, final Level arg2)
         if (!this.sable$added && this.level() instanceof final ServerLevel serverLevel) {
             this.sable$buildProperties();
             this.sable$addToPlot();
-            this.sable$addToPipeline(serverLevel);
+            if (this.sable$massTracker.getCenterOfMass() != null) {
+                this.sable$addToPipeline(serverLevel);
+            }
             this.sable$added = true;
         }
     }
@@ -164,9 +166,12 @@ public CompoundTag saveWithoutId(final CompoundTag nbt) {
 
         assert this.sable$localBounds != null;
         this.sable$massTracker = MassTracker.build(this.sable$blockGetter(), this.sable$localBounds);
-        final Vector3d temp = this.sable$massTracker.getCenterOfMass().negate(new Vector3d()).add(0.5, 0.5, 0.5);
-        for (final FloatingBlockCluster cluster : this.sable$floatingClusterContainer.clusters) {
-            cluster.getBlockData().translateOrigin(temp);
+        final Vector3dc centerOfMass = this.sable$massTracker.getCenterOfMass();
+        if (centerOfMass != null) {
+            final Vector3d temp = centerOfMass.negate(new Vector3d()).add(0.5, 0.5, 0.5);
+            for (final FloatingBlockCluster cluster : this.sable$floatingClusterContainer.clusters) {
+                cluster.getBlockData().translateOrigin(temp);
+            }
         }
     }
 

From f3b5ebd8996537912bb00f6967aec199ee402f41 Mon Sep 17 00:00:00 2001
From: lap2ka <83134094+lap2ka@users.noreply.github.com>
Date: Wed, 20 May 2026 01:55:35 +0200
Subject: [PATCH 2/2] Also prevent NPE for weightless contraptions on sublevels

---
 .../create/contraptions/AbstractContraptionEntityMixin.java     | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/neoforge/src/main/java/dev/ryanhcode/sable/neoforge/mixin/compatibility/create/contraptions/AbstractContraptionEntityMixin.java b/neoforge/src/main/java/dev/ryanhcode/sable/neoforge/mixin/compatibility/create/contraptions/AbstractContraptionEntityMixin.java
index 46ca9001..10703a83 100644
--- a/neoforge/src/main/java/dev/ryanhcode/sable/neoforge/mixin/compatibility/create/contraptions/AbstractContraptionEntityMixin.java
+++ b/neoforge/src/main/java/dev/ryanhcode/sable/neoforge/mixin/compatibility/create/contraptions/AbstractContraptionEntityMixin.java
@@ -98,8 +98,8 @@ public AbstractContraptionEntityMixin(final EntityType<?> arg, final Level arg2)
     private void sable$contraptionInitialize(final CallbackInfo ci) {
         if (!this.sable$added && this.level() instanceof final ServerLevel serverLevel) {
             this.sable$buildProperties();
-            this.sable$addToPlot();
             if (this.sable$massTracker.getCenterOfMass() != null) {
+                this.sable$addToPlot();
                 this.sable$addToPipeline(serverLevel);
             }
             this.sable$added = true;