I downloaded it and grammars worked for me, but the first time I ran I had the same result because I forgot to change this line:
self.pathToFirstDynamicallyGeneratedLanguageModel = [languageModelGenerator pathToSuccessfullyGeneratedLanguageModelWithRequestedName:@”FirstOpenEarsDynamicLanguageModel”];
to this:
self.pathToFirstDynamicallyGeneratedLanguageModel = [languageModelGenerator pathToSuccessfullyGeneratedGrammarWithRequestedName:@”FirstOpenEarsDynamicLanguageModel”];
Is that maybe what you experienced?