HI Alexander, Did your input xml file have the boundary condition information contained in it or was it just a mesh file? This could have caused this problem. Cheers, Spencer. On 6 Apr 2019, at 10:25, A.P. <k210@list.ru<mailto:k210@list.ru>> wrote: Hello, I try to convert a Z-homogenious fld file to an another mesh by FieldConvert module 'interpfield' and recieve this error message: Fatal : Level 0 assertion violation Failed to type cast m_exp[0] terminate called after throwing an instance of 'ErrorUtil::NekError' what(): Level 0 assertion violation Failed to type cast m_exp[0] 2D fields are converted OK. What can be done to overcome the error? Alexander. _______________________________________________ Nektar-users mailing list Nektar-users@imperial.ac.uk<mailto:Nektar-users@imperial.ac.uk> https://mailman.ic.ac.uk/mailman/listinfo/nektar-users Spencer Sherwin FREng, FRAeS Head, Aerodynamics, Director of Research Computing Service, Professor of Computational Fluid Mechanics, Department of Aeronautics, s.sherwin@imperial.ac.uk<mailto:s.sherwin@imperial.ac.uk> South Kensington Campus, Phone: +44 (0)20 7594 5052 Imperial College London, Fax: +44 (0)20 7594 1974 London, SW7 2AZ, UK http://www.imperial.ac.uk/people/s.sherwin/