How to resolve missing layout after importing a GDS file with an encrypted stackup in IC mode simulation?

One possibility is that the layer names in the layermap file do not match those in the encrypted file. If this is the case, HFSS 3D Layout cannot determine which GDS layer maps to which stackup layer in the technology file, and therefore no geometry is imported. To resolve the import issue, edit the layermap file to align the GDS output layers with the encrypted stackup file names.