MPLAB® Snap Troubleshooting

If you are having problems with MPLAB® Snap In-Circuit Debugger operation, start here.

Refer to the MPLAB PICkit™ 4 online help section on "Troubleshooting First Steps". From there you can navigate to “Some Questions to Answer First” and “Top Reasons Why You Can’t Debug.” For general issues involving bootloader mode and emergency boot firmware recovery, see the following sections.


  1. It is possible that the error was a one-time event. Try the operation again.
  2. There may be a problem programming in general. As a test, switch to 'Run' mode in MPLAB X IDE using the icon and program the target with the simplest application possible (e.g., a program to blink an LED). If the program will not run, then you know that something is wrong with the target setup.
  3. It is possible that the target device has been damaged in some way (e.g., over current). Development environments are notoriously hostile to components. Consider trying another target board.
  4. Microchip offers demonstration boards to support most of its microcontrollers. Consider using one of these applications, which are known to work, to verify correct MPLAB Snap In-Circuit Debugger functionality.
  5. Review debugger setup to ensure proper application setup. For more information, see the “Operation” section of the MPLAB PICkit 4 help or PDF.
  6. Your program speed may be set too high for your circuit. In MPLAB X IDE, go to File > Project Properties. Select 'Snap' in "Categories", then 'Program Options' in "Option categories". Select a slower speed from the "Program Speed" drop-down menu. The default is 'Normal'. In MPLAB IPE, the "Program Speed" option can be found in the Advanced Mode, 'Settings' tab.
  7. There may be certain situations where the debugger is not operating properly and needs to be reprogrammed. See the following section.

The Hardware Tool Emergency Boot Firmware Recovery Utility

Brick.jpg CAUTION
Debugger Failure.
Only use this utility to restore hardware tool boot firmware to its factory state.
Use only if your hardware tool no longer functions on any machine

The debugger may need to be forced into recovery boot mode (reprogrammed) in rare situations, for example, if none of the LEDs are lit when the debugger is connected to the computer.

You must use MPLAB X IDE v5.05 or greater to use the emergency recovery utility for the MPLAB Snap.

Carefully follow the instructions found in MPLAB X IDE under the main menu option Debug > Hardware Tool Emergency Boot Firmware Recovery. After the Warning screen, select 'MPLAB Snap'.

Figure 1: Selecting Emergency Utility


Figure 2 shows where the emergency recovery jumper is located on the board.

Figure 2: Emergency Recovery Jumper


If the procedure was successful, the recovery wizard displays a success screen. MPLAB Snap is now operational and able to communicate with the MPLAB X IDE.

If the procedure fails, try it again. If it fails a second time, contact Microchip Support at

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