Post Feko ISAR

I am trying to run the ISAR images example from https://www.altair.com/RelatedCaseStudy.aspx?id=10626 . When I run the PF_ISAR.lua script , I get the error - attempt to call field 'GetApplication' (a nil value).

I am kind of stuck on this error, How best can I proceed?

Regards,

Nyasha