SAMD21 not recognised

I have a few SAMD21 mini breakouts from sparkfun. One of the boards stopped being recognised after being used multiple times. I suspect that the Servo.h sweep program I recently uploaded may have something to do with the error. Has anyone had this issue and if so, how did you solve the problem?

if the sketch doesn’t run, it doesn’t handle the native USB of the MCU. you must activate the bootloader by double reset with the reset buttom. the bootloader will be active for some seconds. select a port and upload a working sketch in that time.

ok, that works, but now I have a completely different issue. Every time the board resets, the Serial port address changes. Right now it ends in usbmodem231, but when I upload a program it becomes usbmodem232 and so on after every reset. This suddenly happened after using the double reset press about ten times. The address used to stay the same after the microcontroller was reset. I can upload sketches but I can't open the serial monitor because the address changes after every upload, so it loses connection with the computer.

Nathaniel_:
ok, that works, but now I have a completely different issue. Every time the board resets, the Serial port address changes. Right now it ends in usbmodem231, but when I upload a program it becomes usbmodem232 and so on after every reset. This suddenly happened after using the double reset press about ten times. The address used to stay the same after the microcontroller was reset. I can upload sketches but I can't open the serial monitor because the address changes after every upload, so it loses connection with the computer.

it will settle once you have a stable sketch. the USB is native in the MCU. at every reset of the MCU, new USB connection is made, but Linux/Mac has the previous name still assigned so a new name/number is assigned. it is better to use a CMIS-DAP programmer/debugger then the USB bootloader. I removed the bootloader from my M0