When I first set-up Eclipse on Mac to allow me to do some debugging on my Crazyflie 2.0, I built and flashed a debug version of the firmware for the first time. The “debug” target in Eclipse creates a build with the parameter “CLOAD=0.” This means that the debug firmware is flashed at the start of the Crazyflie 2.0’s STM32 flash memory. This where the radio bootloader is normally written so, if one existed before flashing debug firmware, it doesn’t exist after it. In any case, I spent a while scratching my head months later when, while trying to update my Crazyflie 2.0 firmware over-the-air (OTA), I found the Crazyradio couldn’t connect to the bootloader! Of course! There wasn’t one there any longer.