diff --git a/examples/miscellaneous/miscellaneous_ex15/miscellaneous_ex15.C b/examples/miscellaneous/miscellaneous_ex15/miscellaneous_ex15.C
index 558f91947c..c290431cf3 100644
--- a/examples/miscellaneous/miscellaneous_ex15/miscellaneous_ex15.C
+++ b/examples/miscellaneous/miscellaneous_ex15/miscellaneous_ex15.C
@@ -221,6 +221,10 @@ int main (int argc, char** argv)
          sync_obj);
     }
 
+  // We'll need to update caches of subdomain ids too, to keep the
+  // mesh prepared.
+  mesh.cache_elem_data();
+
   // Now we set the sources of the field: prism-shaped objects that are
   // determined here by containing certain points:
   auto p_pt_lctr = mesh.sub_point_locator();
diff --git a/src/mesh/mesh_smoother_vsmoother.C b/src/mesh/mesh_smoother_vsmoother.C
index e4261089cf..854b8aa4fd 100644
--- a/src/mesh/mesh_smoother_vsmoother.C
+++ b/src/mesh/mesh_smoother_vsmoother.C
@@ -64,6 +64,9 @@ VariationalMeshSmoother::VariationalMeshSmoother(
 void VariationalMeshSmoother::setup()
 {
   // Check for multiple dimensions
+  if (!_mesh.preparation().has_cached_elem_data)
+    _mesh.cache_elem_data();
+
   if (_mesh.elem_dimensions().size() > 1)
     libmesh_not_implemented_msg("Meshes containing elements of differing dimension are not yet supported.");
 
diff --git a/tests/mesh/mesh_input.C b/tests/mesh/mesh_input.C
index b69dd83415..8dd2f8cbe0 100644
--- a/tests/mesh/mesh_input.C
+++ b/tests/mesh/mesh_input.C
@@ -888,15 +888,19 @@ public:
       MeshType mesh(*TestCommWorld);
 
       EquationSystems es(mesh);
-      System & sys = es.add_system<System> ("SimpleSystem");
-      auto e_var = sys.add_variable("e", CONSTANT, MONOMIAL_VEC);
-      auto e_no_p_var = sys.add_variable("e_no_p",
-                                         FEType(CONSTANT, MONOMIAL_VEC).set_p_refinement(false));
 
+      // We need a mesh.spatial_dimension() *before* adding a
+      // vector-valued variable, so add_variable() can figure out how
+      // many components it needs.
       MeshTools::Generation::build_square (mesh,
                                            3, 3,
                                            0., 1., 0., 1.);
 
+      System & sys = es.add_system<System> ("SimpleSystem");
+      auto e_var = sys.add_variable("e", CONSTANT, MONOMIAL_VEC);
+      auto e_no_p_var = sys.add_variable("e_no_p",
+                                         FEType(CONSTANT, MONOMIAL_VEC).set_p_refinement(false));
+
       es.init();
 
       // Here, we're going to manually set up the solution because the 'project_solution()' and
diff --git a/tests/mesh/mesh_smoother_test.C b/tests/mesh/mesh_smoother_test.C
index e828e9f653..7f499c9761 100644
--- a/tests/mesh/mesh_smoother_test.C
+++ b/tests/mesh/mesh_smoother_test.C
@@ -592,12 +592,15 @@ public:
 
             mesh.comm().sum(distorted_subdomain_volumes[sub_id]);
           }
-
-        // We've just invalidated the get_mesh_subdomains() cache by
-        // adding a new one; fix it.
-        mesh.cache_elem_data();
       }
 
+    // We may have just invalidated the get_mesh_subdomains() cache by
+    // adding a new one, and libMesh marked our spatial_dimension()
+    // cache as invalidated in redistribute().  Just rebuild our
+    // caches before we start asking for anything like
+    // elem_default_orders().
+    mesh.cache_elem_data();
+
     // Get the mesh order
     const auto & elem_orders = mesh.elem_default_orders();
     libmesh_error_msg_if(elem_orders.size() != 1,