Yes on the serial port, except the actual port number. This was filled in as 3481 by Vera. Apparently, that is not correct, based on the error message. (115200, 8, N, 1)
Yes on U17, I think. I downloaded the zip file for U17 and extracted that, then uploaded.

I have a VERA PLUS controller, a mysensors serial gateway(ftdi) and a water leak sensor.
I am trying to get the VERA controller setup to use the serial gateway.
I have uploaded the luup files to the controller.
However, when I created the device I got this error:

GET_LANG(system_error, System error) Device 21. Fail to load implementation file Arduino1.xml.
MySensors plugin: Choose the Serial Port.

My serial gateway is attached to the only USB port on the Vera Plus controller. Where do I find the serial port number?