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.

Mbed driver doesn't work with Windows
If the Mbed Serial driver has been manually installed (by downloading and executing the .exe) it might interfere with the Windows 8/10 automatic installatio...
Wed, 2 Oct, 2019 at 1:42 PM
Sorry, we couldn't recognize this file.
Description This error message will appear in the makecode.microbit.org editor if the .hex file you are trying to load was created in another editor s...
Thu, 21 Feb, 2019 at 11:43 AM
Oops, don't know how to load this file
Description This error message will appear in the makecode.microbit.org editor if the file you are trying to load does not have the required .hex file...
Thu, 21 Feb, 2019 at 11:46 AM
Network request failed!
Description This error message will appear in the makecode.microbit.org editor if the editor cannot connect to another cloud service, for example downloa...
Thu, 21 Feb, 2019 at 12:23 PM
Program Error: r.isRef is not a function
Description This is a generic error that will appear in the makecode.microbit.org editor if there is an issue with the program when it is run thorugh ...
Thu, 21 Feb, 2019 at 2:15 PM
Safari has a bug that means your work will be downloaded as an un-named file. Please rename it to something ending in .hex. Alternatively, use a browser such as Firefox or Chrome. They do not suffer from this bug
Description This error message will appear in the python.microbit.org editor when you try to download a .Hex file using Safari on MacOS. The file will down...
Mon, 11 Mar, 2019 at 1:04 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 python.microbit.org 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 python.microbit.org 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 python.microbit.org 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
WebUSB Troubleshooting
The Web USB API facilitates communicating with USB devices from the browser. The API is currently available in Chrome based browsers and is supported in the...
Tue, 5 Nov, 2019 at 12:38 PM