What is wrong with arming?

I just updated my firmware and realised

								1, # autopilot system id
								1, # autopilot component id
								400, # command id, ARM/DISARM
								0, # confirmation
								1, # arm!
								0,0,0,0,0,0 # unused parameters for this command

This doesn’t work?

I search the mavlink common page, no command_long command?

What exactly is the problem how do I arm my drone now using command?

I found the issue. Its because that the system id in command long must be the same system id as per what is in the parameters.