challenger 650. I cannot engage Autopilot

[gayt]

challenger 650
When I press the AP button, the AP does not engage.

[Pils]

The aircraft must be in trim, and the button must be held down for a few moments.

If you're still having trouble, please provide a video, preferably in high resolution.

[mtmurat]

When it does this, try pressing the big red disconnect button on the yoke under your thumb. That resets the AP. Also make sure the AP bar on the panel is not pushed down.