On the Original Prusa XL, the I2C bus is used for the XLBuddy to communicate with other printer components. If there is an error in sending data from the XLBuddy, the printer will show the message "HAL detected an I2C error when sending data via I2C."
Error name: I2C Send Failed
Error code: #17311
Restarting the printer is expected to resolve the error, and this is not expected to occur again.
If the issue appears again, download the firmware and if necessary the bootloader, and transfer it to your USB drive. Make sure to unmount the drive from your operating system before physically removing it.
Insert the USB drive back into the printer and reboot the printer using the reset button directly next to the knob to initiate the flashing procedure. In case the procedure does not start, reboot the printer again by pressing the same reset button, and while the printer is booting up, press once the rotating knob.
In case that also does not solve the issue, please contact our customer support, and we will take it from here.