Okay, I forgot to list Igor as isHim = true.
This (ugly) approach will get the parser to comply:
+ igor: Actor 'igor' isHim = true ;
++ igorsName: Thing 'his name' ; //make invisible
++ AskAboutForTopic @igorsName "Igor is his name, oh! " ;
And I note that Lite does not need the extra grammar I made in order to field ‘ask igor his name’…