Exception in Pipeline tool when using the latest version

I use the latest source version of the pipeline tool. Now when I open up a mgcb file and add content I get an exception when selecting an item in the added folder.

The exception occurs in the line 79 of CellBase.cs which is:

g.DrawText(SystemFonts.Default(), DrawInfo.GetTextColor(selected, !Editable), separatorPos + 5, rec.Y + (rec.Height - Height) / 2, DisplayValue);

If I comment the line out I get no exception but then the pipeline tool looks like this: