The HMS message happens when AP detects that the MC module is malfunctioning.
The MC module errors that AP can detect can be:
Check the communication between AP and MC and check if MC board works well.
https://wiki.bambulab.com/en/x1/maintenance/replace-mc-board
https://wiki.bambulab.com/en/x1/maintenance/replace-ap-board
https://wiki.bambulab.com/en/p1/maintenance/mc-board
https://wiki.bambulab.com/en/p1/maintenance/mc-ap-cable