As the problem will be probably fixed in a future version of MATLAB, and the script is constrained to use a MATLAB version <= R2017b (see https://github.com/robotology/simmechanics-to-urdf/issues/39), this probably means that this script will never support PTC Creo 9.
This is an important annoucement for anyone using this plugin to export URDFs from creo. Due to an incompatibility between PTC Creo 9 and , that you can find documented in https://it.mathworks.com/matlabcentral/answers/1879607-incompatibility-between-ptc-creo-9-and-simscape-multibody-link#answer_1144727?s_tid=prof_contriblnk , at the moment this script does not work with PTC Creo 9.
As the problem will be probably fixed in a future version of MATLAB, and the script is constrained to use a MATLAB version <= R2017b (see https://github.com/robotology/simmechanics-to-urdf/issues/39), this probably means that this script will never support PTC Creo 9.
fyi @vpunithreddy @gabrielenava @FabioBergonti