diff --git a/Minecraft.World/Network/Packets/SetEntityMotionPacket.cpp b/Minecraft.World/Network/Packets/SetEntityMotionPacket.cpp
index bff87c5bd..cb6d2a42c 100644
--- a/Minecraft.World/Network/Packets/SetEntityMotionPacket.cpp
+++ b/Minecraft.World/Network/Packets/SetEntityMotionPacket.cpp
@@ -73,18 +73,20 @@ void SetEntityMotionPacket::read(DataInputStream *dis) //throws IOException
 	}
 }
 
-void SetEntityMotionPacket::write(DataOutputStream *dos) //throws IOException 
+void SetEntityMotionPacket::write(DataOutputStream *dos) //throws IOException
 {
 	if( useBytes )
 	{
-		dos->writeShort(id | 0x800);
+		// Masking the id to 11 bits before writing to account for large entitty ids.
+		dos->writeShort((id & 0x07FF) | 0x800);
 		dos->writeByte(xa/16);
 		dos->writeByte(ya/16);
 		dos->writeByte(za/16);
 	}
 	else
 	{
-		dos->writeShort(id);
+		// same thing as line 80 here
+		dos->writeShort((id & 0x07FF));
 		dos->writeShort(xa);
 		dos->writeShort(ya);
 		dos->writeShort(za);
diff --git a/flake.nix b/flake.nix
index 24d0e6679..9897d7fc6 100644
--- a/flake.nix
+++ b/flake.nix
@@ -32,6 +32,7 @@
         libvorbis
       ];
       packages = with pkgs; [
+        python3
         gcc15
         lld
         cmake
diff --git a/scripts/copy_assets_to_client.py b/scripts/copy_assets_to_client.py
index 9670a2dcb..6e69231f4 100644
--- a/scripts/copy_assets_to_client.py
+++ b/scripts/copy_assets_to_client.py
@@ -23,11 +23,11 @@ src_assets = Path(project_source_root / "Minecraft.Assets")
 
 # clear out any old assets
 if dest_common.exists():
-    shutil.rmtree(dest_common)
-    shutil.rmtree(client_build_dir / "music")
-    shutil.rmtree(client_build_dir / "Sound")
+    shutil.rmtree(dest_common, ignore_errors=True)
+    shutil.rmtree(client_build_dir / "music", ignore_errors=True)
+    shutil.rmtree(client_build_dir / "Sound", ignore_errors=True)
     # XXX: Check "copy DLC" bellow for info
-    # shutil.rmtree(client_build_dir / "DurangoMedia")
+    # shutil.rmtree(client_build_dir / "DurangoMedia", ignore_errors=True)
 
 # copy `Minecraft.Assets/Common` into the build directory for the client.
 shutil.copytree(