I'm using Gtn 750 in Bell 412.  Because of outdated airac cycle cannot get Autopilot to follow fpln Magenta line ?.

Hi! The GTN 750 is a great GPS navigator, but it does require an up-to-date AIRAC cycle in order to function properly. If you're using an outdated AIRAC cycle, the autopilot may not be able to follow the magenta line on your flight plan.

I use it with outdated navdata and AP just works fine then.