Close other copies of Scratch

Only one copy of Scratch can connect with the micro:bit at a time. If you have Scratch open in other browser tabs, close it and try again.

Make sure no other computer is connected to your micro:bit

Only one computer can be connected to an micro:bit at a time. If you have another computer connected to your micro:bit, disconnect the micro:bit or close Scratch on that computer and try again.

Make sure you aren’t hitting the “reset” button

Sometimes while using the micro:bit you can accidentally press the “reset” button on the back in-between the USB and power ports. Make sure you keep your fingers (and toes) away from it while using Scratch!