I've just installed 6 new e1200 Pro on my s900.
I get the led below each one of them, and I can test each one of them on assistant software 2.
But when trying to change led color and check firmware version with ESC software, M1 does not connect to ESC software. The others connect OK and I was able to change to RED the led color of motor M2. The ESC usb adapter has its led green like with the others motors, and when I open ESC software the red led insode the ESC adapter also turns on, as with the others. But the software does not connect.
Any help appreciated

Pablo

Unplugging the signal wire (the one that comes from the motor arm to M1 connector on s900 plate) did the trick. It allows me to connect to ESC software.