cause of issue:
The communication between the encoder and the servo module is incorrect, and the data cannot be transmitted normally.
There are three links involved in the alarm: encoder, cable, and servo module.
Check the cable interface first, and then gently shake the cable to see if there is an alarm. If so, repair or replace the cable.
After eliminating the cause of the cable, the replacement method can be used to further confirm the encoder and servo module.