Dear all, I am a new user. When I tried the VCSMapping with test case (nektar/solvers/IncNavierStokesSolver/Tests/CylFlow_Mov_mapping.xml) it failed to run in parallel with errors: " mpirun -np 8 IncNavierStokesSolver CylFlow_Mov_mapping.xml Fatal : Level 0 assertion violation A parallel solver must be used when run in parallel. " I had to run it in serial to get the final result. However the mesh grid and the position of cylinder remain the same as initial field, even if I have tried different "NumSteps". I just followed the user guide and used "FieldConvert CylFlow_Mov_mapping.xml CylFlow_Mov_mapping.fld cyl.vtu" to get the converted result. I guess maybe because 'CylFlow_Mov_mapping.xml' only contains initial mesh data and CylFlow_Mov_mapping.fld only contains field data, i.e., deformed mesh information is missed by this command. so I think this problem is about post-processing. Could you please help to find out what I've missed and fix this problem? I would appreciate your Help. Kind regards, Hanbo