@Tom - I use the same classes in one of my projects, and I installed it in exactly the same way as you do. I can generate the same errors that you're seeing - but only if I remove import
Charts
from my class definition.
Here's what the start of my class definition looks like
import UIKit
import Charts
class SharePriceGraphViewController: UIViewController, ChartViewDelegate
{
var myStickChart: BarChartView! // I don't really have this - added for this test :-)
as it stands, this compiles nicely. if I remove the import - I get the same error as you do.