Pidome problem setting up sensors

[chrismills]

Hi there, I'm a noob here and I was wondering if anyone could offer some advice.

I am having trouble adding devices to my PiDome setup.

I have a MySensors Serial Gateway and Motion Controller. These are running on Arduino Nano and seem to be working (using Arduimo Serial Monitor).
I have installed Pidome on my RPi following all instructions I can find (I think). This seems to be working also. I can access the Web Interface at https:// 192.168.1.###:8080.

I have conneccted my gateway to RPi via USB and Pidome recognizes it and allows me to install using MySensors USB driver API 1.5

Then device discovery identifies and unknown device via serial

From here I can enter details into "Discovered Device" popup but when I click Add and start I get an Error message:Problem creating device: Could not add a device: Save error, refer to log file.

I can't help but wonder if permissions are not set up correctly but any advice would be welcome.
Thanks
Chris