If troubles persist, please feel free to send our support team a sample file (https://numericalinnovations.freshdesk.com/support/tickets/new), and we'll be happy to create a tutorial movie showing how to convert your file to 3D. If possible please include what layers should be converted an the thicknesses.
Simon Garrison
Thanks for contacting us here's a specific tutorial movie showing how to convert GDSII to STL, using ACE,
https://numericalsoftware-update.s3.amazonaws.com/tutorials/2018-04-16_10-00-09_GDS_3D_BuildStackup.mp4
If troubles persist, please feel free to send our support team a sample file (https://numericalinnovations.freshdesk.com/support/tickets/new), and we'll be happy to create a tutorial movie showing how to convert your file to 3D. If possible please include what layers should be converted an the thicknesses.
Best regards,
Simon