Apm 2.8 firmware install error

To arm motors, I held down the left stick to bottom right for few seconds but nothing is happening

What is written on the ground station ?

Infact now, i cannot connect through USB again, it’s not indicating any light, but if i plug the battery, light flashes on the board, but no light flash with USB

Before now, I connected the drone via USB and try to ARM and DISARM it, it was responding on the flight data from my PC screen and I could see that I was connected to 10 SATELLITES. But anytime when I connected battery, the light indicator shows ARMED (SOLID red) and DISARMED (FLASHING red and the blue). Or could it be battery voltage has dropped from required? because the battery (3S 3000mAH, 11.1V) is now showing 8.87V.

The other problem is that of the Board not indicating light when connected via USB but works when connected to battery