Hmm i think i have same problem before. I think this is some old engine predefined variable from A4 time (in most chase used in particles), but this wont work anymore in A8.
Correct me if i wrong?!

EDITED:
Sorry i wrong, i thinking on "my_age" and my_angle should be used for templates. I never before work with templates but maybe my_angle no longer exists in the A8?