For a couple of months my Taranis throttle stick has been stuck and wouldn't zero out. The default position is about 5% throttle. Every time I turn on my Taranis I get the "Throttle Warning" message, which is very annoying.
In this video I demonstrate how to open up your Taranis and adjust a screw on the throttle/rudder gimbal to zero your throttle stick. After adjusting the stick make sure you do a stick calibration with OpenTX. Now I'm not entirely sure that it's necessary, but it doesn't hurt to know how to do it.