I just downloaded MatterControl 2.0 on my Windows 10 desktop. I do not start MatterControl, but started S3D and see it is using com10 and a baud rate of 115200. I close S3D and open MatterControl. I went to the top lright 'vertical dots' and selected Configure printer, went through the steps of correcting my bed size (300x220) and build height to 300. and set the baud rate.
Then on the top left, I select connect and it acts like it connected, but none of the controls work to home or preheat bed and extruder. I opened the terminal window and it says, "Communication State: AttemptingToConnect
N1 M110 N1*125
Communication State: Connected
Read Thread Has Exited.
I can't print or anything. Windows Device Manager shows Com10 as "USB Serial Port", which it is.
S3D prints to the machine and controls it through the same port fine.