Please post the full part number of your Panelview. The firmware in the Panelview (if it is a standard) may also come into play with regard to accessing Controllogix tags. Also, PLC/SLC tag mapping may be of use to you.
It is also very useful if you can post copies of your application(s). Zip them first (right click the file, send to compressed folder), then attach to a post in this thread.
Welcome to the forum, by the way.