Voyage Planner and Navionics charts

I have just purchased and installed VoyagePlanner 1.3.0.8.

I am having difficulty in importing my navionics plus charts. The charts were purchased in June of 2015 and they are under a current update plan. On the media (a microSD) I can see the nTag.txt file however VoyagePlanner claims it can not find it. The number in the file is: US1I771PM6BGSU.

Any thoughts?

-Bob.