A menu is open on the video screen

Stops itRangefinder, optical flow, camera, OSD and other devices

What ArduPilot says:

In OSD menu

Arming is refused while a menu is open in the goggles or on the monitor, because the sticks are being used to move through it. Two things raise this: ArduPilot's own OSD showing one of its parameter screens (screens 5 and 6, where values are changed with the sticks), or a RunCam camera whose settings menu was opened from the transmitter.

What to do, most likely first

The OSD screen switch stands on a parameter screen.
CheckOSD_CHAN names the channel that changes screens; the picture shows a list of parameters instead of the flight display.
FixMove the screen switch to one of the flight screens (1 to 4). If you never use the parameter screens, set OSD5_ENABLE and OSD6_ENABLE to 0.
The RunCam camera's own menu is open.
CheckThe camera's settings are drawn over the picture.
FixPush the roll stick left until the menu closes, then arm.

Parameters to look at

Parameter	What it is
`OSD_CHAN`	Screen switch transmitter channel
`OSD_SW_METHOD`	Screen switch method
`OSD5_ENABLE`	Enable screen
`OSD6_ENABLE`	Enable screen
`OSD_TYPE`	OSD type

The code that sends it

In OSD menu

libraries/AP_Camera/AP_RunCam.cpp AP_RunCam::pre_arm_check() · Open in ArduPilot Copter-4.7.1

libraries/AP_OSD/AP_OSD.cpp AP_OSD::pre_arm_check() · Open in ArduPilot Copter-4.7.1