On the Original Prusa XL, the I2C bus is used for the XLBuddy to communicate with other printer components. The components have different states, including a busy state: if this particular state occurs while data is being sent from the XLBuddy, the printer will show the message: "HAL detected an I2C busy state when sending data via I2C."
Error name: I2C Send Busy
Error code: #17312
Restarting the printer is expected to resolve the error, and this is not expected to occur again. In case a restart does not resolve it, please contact our customer support, we will take it from here.