From the documentation in the InstructionCard this should work ...
FlexWiki.TopicContextDemo(1:14) : No such property or function: Type.CurrentTopic... but doesn't
Your sample has a minor error in casing
@@TopicContext.CurrentTopic.FullName@@
should be
@@TopicContext.CurrentTopic.Fullname@@FlexWiki.TopicContextDemo(1:14) : No such property or function: Type.CurrentTopic