I do not have an "Add Files" button on my screen.
The 'Add Files' button is controlled by a specific ActiveX component.
If you do not have the component installed, you will be prompted to install it as soon as you click the "Upload Roster" link. Look for a pop-up box or a message in the Information Bar asking you to install the ActiveX file. Once the file is installed, the Add Files button will appear on your screen.
If you do not get prompted or if you are still unable to get the 'Add Files' button, please contact NWEA Technical Support.