@Thot, thanks again for your help.
The Mx28 dynamixel have the firmware 39 ( they came like this when they were bought). They were working with ROS with dynamixel package and Python with PyPot as well using USB2AX.
The humanoid was working with all motors. However, from one moment to another, the servos stopped being recognized.
At this moment, I am using RoboPlus 22.214.171.124. This tool has Dynamixel Wizard 126.96.36.199.
I am doing a firmware recovery in order to get the firmware 36.
When I search the motors individually using USB2AX, dynamixel wizard recognizes the motors.
However, some motors are not found when USB2Dynamixel is used. (Some motors are found).
The recovery firmware only is working in that motors that are found using USB2Dynamixel. This is, using USB2AX the recovery firmware fails in the motor detection. Only USB2Dynamixel works. But, as mentioned, USB2Dynamixel does not detect all motors individually.
In this video I show this problem