Your micro:bit may encounter a situation that prevents it from running your code. When this happens, a frowny face will appear on your micro:bit screen (see picture) followed by an error number.
Below is a list of error numbers and what they mean:
* **10** (`MICROBIT_I2C_LOCKUP`): the micro:bit's I2C bus is not working
* **20** (`MICROBIT_OOM`): there is no free memory on the micro:bit
