On the Original Prusa MK4/MK3.9/MK3.5, the I2C bus is used for the xBuddy board to communicate with other printer components. If there is an error in sending data from the xBuddy board, the printer will show the message: "HAL detected an I2C error when sending data via I2C."
Error name: I2C Send failed
Error code: #26311 (MK4S) #13311 (MK4) #21311 (MK3.9) #23311 (MK3.5)
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.