NuHeat plugin issues

I've upgraded my NuHeat system to include the Signature thermostat. It's up and running well. However, when I tried to use the Indigo plugin, no luck. After installing the plugin and adding the type and model information, I couldn't go any further. Clicking on the Edit Device Settings opened up a small window. It didn't show the thermostat or allow me to add any additional information. Even the Read Me file wouldn't open. My computer thought it was a Moneydance financial file.

If you have some additional information, I'd be grateful to receive it.

Thanks!

/ap