[whereswaldo]

A quick fix for this is to edit the module referenced in the error message (Interface\AddOns\nUI\Units\nUI_UnitFrame.lua) and replace "this" with "self"

Before

				if popup then
						
					local anchor = frame.popup and frame or frame.parent;
					this.unit    = frame.unit;
					this.id      = id;
					this.name,
					this.server  = UnitName( frame.unit );
								
					ToggleDropDownMenu( 1, nil, popup, anchor, anchor:GetWidth()/2, anchor:GetHeight()/2 );
					
				end

After

				if popup then
						
					local anchor = frame.popup and frame or frame.parent;
					self.unit    = frame.unit;
					self.id      = id;
					self.name,
					self.server  = UnitName( frame.unit );
								
					ToggleDropDownMenu( 1, nil, popup, anchor, anchor:GetWidth()/2, anchor:GetHeight()/2 );
					
				end