When working with WebParts, within the ZoneTemplate tag inside a WebPartZone you add user controls. When you do, you must add a title attribute to the user control to have it displayed correctly on the page. R# does not understand the title attribute, marking with a green squily, and in the icon bar displays it red. As I make it a strong rule that until I see green, I do not compile, this is a problem.
<uc2:CalendarControl title="Calendar" ID="calendar" runat="server" />