--- a/net/minecraft/world/level/block/entity/TestBlockEntity.java
+++ b/net/minecraft/world/level/block/entity/TestBlockEntity.java
@@ -36,6 +_,7 @@
 
     @Override
     public void loadAdditional(CompoundTag tag, HolderLookup.Provider registries) {
+        super.loadAdditional(tag, registries); // Paper - load the PDC
         this.mode = tag.read("mode", TestBlockMode.CODEC).orElse(TestBlockMode.FAIL);
         this.message = tag.getStringOr("message", "");
         this.powered = tag.getBooleanOr("powered", false);
