Line chart lines are invisible?

Aug 13, 2014 at 9:20 PM
Edited Aug 13, 2014 at 9:23 PM
Hello! I'm trying to create a line chart using EPPlus Beta 4.0 (I've also tried 3.1) and having a bit of trouble. For some reason the lines of the line chart end up invisible. Any idea what's going on? Here's my code:
ExcelLineChart ec = worksheet.Drawings.AddChart("Line Time Graph", OfficeOpenXml.Drawing.Chart.eChartType.Line) as ExcelLineChart;
            ec.Title.Text = "Monthly Data";
            ec.SetPosition(1, 0, 4, 0);
            ec.SetSize(800, 600);

            ec.DisplayBlanksAs = eDisplayBlanksAs.Span;

            ExcelChartSerie s1 = ec.Series.Add("B7:B18", "A7:A18");