Why won't my variables resolve in my canned responses?

[NancyB455]

I am getting ready to teach a class encouraging people to use canned responses.  When I first tested adding variables, I tested one and it worked fine but now, they don't resolve.  They just show up in the comment email as, for example,  ${issue.description}

I have tried adding the canned response in both visual and text mode - no change.

Any ideas?