Praneeth
Ansys Employee

Hi mosfet,

Thank you for reaching to us and we appreciate your patience.

Please note that the principal axis of must align with port normal as given in the error message. You can find detailed information on anisotropic materials in the HFSS help document. To start, kindly go through "Defining Anisotropic Tensors", "Changing the Orientation of an Object", "Anisotropic Materials", "Tensor Entries", "Anisotropic Relative Permittivity Tensors".

All the very best,
Praneeth.