1277 error on GSK218M

CNC Milling Machine user:
Hello sir, there is 1277 error on GSK218M, PLC external error, coolant motor overloaded, what happened?
CNCmakers Support:
There is no 1277 error on GSK218M, but there is 1277 error on GSK218MC, which means: tool holder is not in position which cause the tool bank not able to rotate.