When I tap the battery twice to enter the gesture mode nothing happens at all. I had no problem before,maybe a hardware problem? Thanks

Does the camera move up and down and try to read your face or does it literally do nothing?

Yes, the camera responds

have you tried to have the mobile conected while you are doing that to see if any error messages are popping up on the screen?

connect your spark to your phone, or to the controller, whichever you have. in the menus, there should be an option that says "enable advanced gesture control" or something like that. Enable that, power down remote/phone and drone, and then try. also note that you have to power on the drone before double tapping the power button to enable gesture mode.

New battery?  A new battery without the firmware update?  Mine looked at me blankly and wouldn't take off in gesture mode because of that.

is double tapping the drone for gesture mode just added? because I did not read anything about this

Its how you hand launch the Spark and if you hand launch it automatically goes into Gesture mode (or at least mine does).

Mine has failed to hand launch a few times. Like yours the camera searches up and down to recognise you but doesn't, an error message will appear on your phone/device screen and just just try again. Obviously make sure the AC/RC/batteries all have the latest firmware on them.

You need to turn the drone on, and than touch twice

Try turning off beginner mode.

Loritom, please ensure that the drone detact your face successfully. Please tell me the colour of the indicator of your drone. Keep us updated, thanks.