use MSH2.2 here

GetDDM/sphere_concentric.geo

@@ -8,6 +8,7 @@ Include "sphere_concentric_data.geo";
 
 Solver.AutoMesh = -1; // the geometry script generates the mesh
 Mesh.Optimize = 1;
+Mesh.MshFileVersion = 2.2;
 
 If(N_DOM < 1)
   Printf("Hey Dude, stop kidding me :-)");