The error seemed to be related to default material data:

”Here, we also provide you with a default property list saved in default_props_fsp.mat, which is used to remove some redundant property settings in your final script. You can also generate this file by running get_default_property_list.lsfx. Using the script files provided here, the obtained final script will use the long format and include all parameter values. A shorter version of the script file can be obtained by setting the skip_default to ‘true’ in the Lumerical_project_to_setup_script.lsf.”


Therefore, before running “the Lumerical_project_to_setup_script.lsf along with the project file opened in the IDE.”


Make sure to “download and keep the attached files in the same folder.”


If the above details have been followed through and the problem persists, there are some troubleshooting procedures in the comments:

”# Troubleshooting:
#     > In cases where the setup script generates error in setting a particular parameter value,
#       try adding that parameter in the “do not set” list in the “generate_do_not_set.lsf” file.
#     > The user should further test the project file when setting skip_default to be true and switch it  
#       to false if any error occurs.”