Hi,
Still having issues with the lastest update on a Dell Chromebook 11:
it seems flashing to ttyACM0 is the problem, while the Serial monitor just works on ttyACM0, not on USB0
when switching to USB0 the first time, the flash succeeds, but after that both ways fail.
After removing the arduino, the option switches back to ttyACM0, but setting it back to USB0, then flash succeeds.
and keeps working, until you have to open the serial monitor ( which doesnt work on ttyUSB0)
serial monitor always shows ttyACM0, you cannot change it to USB0 anymore, until you remove the device and reinstall it
to sum it up:
Plugin device and start arduino create, select USB0 as port and flashing works. (several times)
Opening the Serial monitor, always changes to ACM0, which is unable to flash.
Only way to solve it is to close the serial monitor and remove the device and reinsert it, after wich you can switch back to USB0
