When I was trying to generate 3D tetrahedral mesh using:
MeshTools::Generation::build_cube (mesh, 20, 20, 20, -3., 3., -3., 3., -3., 3., TET10);
ERROR: Unrecognized 3D element type.
 src/mesh/mesh_generation.C, line 671, compiled Jun 13 2006 at 23:07:35
I thought TET4 and TET10 elements were implemented in libmesh because they are listed under Generic 3D Finite Elements of libmesh Class DOCs
Alternatively I tried tetgen with libmesh using:
TetGenMeshInterface tetgen (mesh);
And the program threw an error at
and  src/fe/fe_lagrange.C, line 614
Can anyone tell me what could be the problem?