I understand that this is a frequent problem but Googling hasn't led to a solution yet in my case. Assembly of the new Anycubic linear went well as did uploading the latest firmware to the board with Arduino (1.8.1). The CP210x driver automatically installed itself upon USB insertion, on Com 3 at 9600 according to Device Manager. After closing the Arduino app the next step is said to be openinby papilio - Reprappers