I have a custom board that is not playing the game. When I try to upload a sketch I get this error.
It does have power as there is a display attached and it works. The progammer (jtag2UPDI) is also working I think as the custom board resets when I try to program it. The HV pulse LED flashes as it should. The custom board is powered by a seperate 12V power supply with a 5V reg on the board. All the grounds are connected.
The Custom board was able to be programmed before but I have added the programming and power to a custom test box. I have checked and rechecked the wiring many times.