I recently ran into problems with upgrading my Tone 2 Pro to v1.2 with MCU upgrade. Xmos upgrade went flawless. But after MCU upgrade I received the following error on ST Tool: Cannot communicate with the device. Check the SWIM cable connection and check all the needed pin connections on the SWIM connector. After this the Tone 2 Pro flashed green even after I reset cable. The Tone 2 Pro was no longer recognized by the PC and looked like it was proper fried. I tried repeatedly to update the firmware (20x) but it just wouldn’t go. I followed all instructions on video and blog perfectly. After ten days of not working and not getting much help from Khadas, I was fed up and contacted Amazon to see if I could return the unit; the tech there suggest I try the machine on another device, I plugged it into my Android phone and the unit finally rebooted (reset) and the flashing green light finally turned back into the volume button. Not only does the unit now work with all my devices, it sounds a whole lot better than I remember – so the problems discussed on audiosciencereview do hit the audible level. I assume the problem I was having was that the unit simply wouldn’t reset after the upgrade so the PC wouldn’t recognize the device. Have a phone available if you decide to upgrade.
did you put a small lateral pressure on the three connectors at the end of the cable to be sure that they were in contact with the Tone2 Pro ?
Your error message is what I got the first time, then I just checked that the Tone2 Pro was powered (USB cable on I2S port) and add a bit of pressure, started the update again and everything worked.