Errors & Troubleshooting

Occasionally the editor or app you are using will throw an error. Common errors are listed here with a description of what they mean and what you can do to resolve them.

Bluetooth troubleshooting guide
If you are having issues with bluetooth and your micro:bit, you'll find a comprehensive diagnostic guide (attached) to download (1.5Mb).
Mon, 10 May, 2021 at 12:37 PM
Safari has a bug that means your work will be downloaded as an un-named file. Please rename it to something ending in .py. Alternatively, use a browser such as Firefox or Chrome. They do not suffer from this bug.
Description This error message will appear in the editor when you try to download a python script .py file using Safari on MacOS. The f...
Mon, 11 Mar, 2019 at 1:04 PM
Oops! Your script is too long given the limited memory on the device.
Description This error message will appear in the editor if you try to download a hex file that contains too many lines of code. R...
Mon, 11 Mar, 2019 at 2:48 PM
Sorry, we couldn't recognise this file
Description This error message will appear in the editor if the .hex file you are trying to load was created in another editor such as...
Mon, 11 Mar, 2019 at 2:51 PM
Why does MicroPython on and Mu work differently?
The MicroPython editor hosted on the website follows a different update cycle to the Mu editor. Both MicroPython on the webs...
Fri, 15 Feb, 2019 at 12:24 PM
Incorrectly named .hex files fail to upload
You may find that the .hex file fails to be flashed to your micro:bit, resulting in the file briefly appearing on the micro:bit device, alongside a FAIL.txt...
Tue, 16 Oct, 2018 at 9:01 AM
Yotta registry deprecation
This is an important update about the yotta registry, which is used to build the microbit-dal and related projects for the BBC micro:bit V1. What is chan...
Tue, 2 Mar, 2021 at 9:07 AM
Why can't I use the Bluetooth and Neopixel packages at the same time?
Unfortunately, It's not currently possible to do this because the NeoPixel library needs fast uninterruptible timeslots to get accurate data sent to th...
Tue, 26 Jun, 2018 at 12:01 PM doesn't load on Chromebook
If you find that when you load the MakeCode Editor that elements of the editor are missing or it gets stuck loading a new project: that you meet the firewal...
Tue, 23 Jun, 2020 at 10:51 AM
Search not working in the Makecode Editor/Can't add extensions
When tryting to add an approved extension, you may be presented with a message saying 'We couldn't find any packages matching...'. T...
Tue, 23 Jun, 2020 at 10:49 AM