CircuitPython is a programming language designed to simplify experimenting and learning to program on low-cost microcontroller boards.
Currently, the File Glider App requires a Circuit Playground Bluefruit board running the most recent build of CircuitPython 7. If you haven't already, you'll need to download the latest version of CircuitPython from the link below. For more on CircuitPython, check out this guide.
Plug your Circuit Playground Bluefruit into your computer using a known-good data-capable USB cable.
A lot of people end up using charge-only USB cables and it is very frustrating! So make sure you have a USB cable you know is good for data sync.
Double-click the small Reset button in the middle of the CPB (indicated by the red arrow in the image). The ten NeoPixel LEDs will all turn red, and then will all turn green. If they turn all red and stay red, check the USB cable, try another USB port, etc. The little red LED next to the USB connector will pulse red - this is ok!
If double-clicking doesn't work the first time, try again. Sometimes it can take a few tries to get the rhythm right!
(If double-clicking doesn't do it, try a single-click!)