The problem is most likely caused by a faulty or non-existent
communications port.
- 1.Reconnect to the MPLAB PICkit 4 In-Circuit Debugger.
- 2.Make sure the debugger is physically connected to the computer on
the appropriate USB port.
- 3.Make sure the appropriate USB port has been selected in the
debugger options (see Debugger Options Selection).
- 4.Make sure the USB port is not in use by another device.
- 5.If using a USB hub, make sure it is powered.
- 6.Make sure the USB drivers are loaded.