Finally it works... but when I'm in a camera view the "Render with Indigo" turn grey so I can't click on it.
If I click in a normal view there is an error msg "No 3D View found in the document" and the exporting progress bar freeze, but I have a couple of camera views in the project navigator!... could be because of the spanish version of revit?.
If I click in "Indigo render settings" there is an error related to Net Framework "InvalidArgument0Value of '0' is not valid for 'SelectedIndex'."
glad you got it working! What was the problem?
You have to select a camera in the Indigo settings dialog before you can render a scene.
About the error you get when you open the settings dialog:
This is an issue that I really need to fix. If you just click "continue" in the error dialog it will work and the error will not show up again.