Sci_cosim Issue

Hi i was trying to run the example file sci_sim_example, as indicated here
<https://wiki.octave.org/Sci_cosim>. However, it is not working at all, it
returns the following message:

*>> sci_sim_example*
*error: 'argn' undefined near line 19, column 19*
*error: called from*
*    sci_setvar at line 19 column 9*
*    sci_sim_example at line 20 column 3*


Appreciate any help or guidance.

Regards,