What do the LED colours mean on a RYOBI 18V ONE+ HP Brushless 30-34° Framing Nailer?

LED Indicator Guide – RYOBI 18V ONE+ HP Brushless 30–34° Framing Nailer

• Steady green: The tool is activated and ready to fire nails.
• Steady red: The battery is low and should be recharged or replaced.
• Flashing red: The tool is in protection mode, which may be caused by a jammed nail.
   

For help clearing jams, see:
How to Remove a Jammed Nail from a RYOBI 18V ONE+ HP Brushless 30–34° Framing Nailer