Install the latest PATCH, version 2.17.02 from this link (MAKE SURE YOU DOWNLOAD THE PATCH INSTALL, the second link on this page, and NOT the full version:
http://www.pokertracker3.com/products/PTH/download.phpThen go to the Summary tab of the Ring Stats window, click somewhere in the bottom data section and hit the F3 key. At the top right corner of the top data section a button should appear called Fix Missing Players. Click on it. When it's done, close and reopen the window.