diff --git a/src/DynamoCoreWpf/ViewModels/Watch3D/HelixWatch3DViewModel.cs b/src/DynamoCoreWpf/ViewModels/Watch3D/HelixWatch3DViewModel.cs
index 7229a634ea7..ea9c7aad510 100644
--- a/src/DynamoCoreWpf/ViewModels/Watch3D/HelixWatch3DViewModel.cs
+++ b/src/DynamoCoreWpf/ViewModels/Watch3D/HelixWatch3DViewModel.cs
@@ -909,7 +909,9 @@ public override void GenerateViewGeometryFromRenderPackagesAndRequestUpdate(Rend
             renderTimer.Start();
 #endif
             var packages = taskPackages.Packages;
-            var meshPackages = packages.Cast<HelixRenderPackage>().Where(rp => rp.MeshVertexCount % 3 == 0);
+
+            var meshPackages = packages.Where(renderPackage => (renderPackage as HelixRenderPackage)?.MeshVertexCount % 3 == 0)
+                .Select(renderPackage => renderPackage as HelixRenderPackage);
 
             RemoveGeometryForUpdatedPackages(meshPackages);
             try