abgqq pokerSerialException: could not open port 'COM3' WindowsError(5 ; WebJun 21, 2018 · Hi Flint, I suspect that both errors (from serial and pyxid) reflect the same underlying problem, namely that the device is simply not there.If you go into the Device Manager of Windows, you can see a list of all COM ports. Is COM3 there? I suspect not. SerialException: could not open port 'COM3' WindowsError(5 … ; WebJun 21, 2018 · Hi Flint, I suspect that both errors (from serial and pyxid) reflect the same underlying problem, namely that the device is simply not there.If you go into the Device Manager of Windows, you can see a list of all COM ports. Is COM3 there? I suspect not.