NameCoach's Name Pages remember where you are / what you are doing between sessions, including search / sorting behavior for each tab on your Name Page.
Sometimes this can make it look like some or all of your participants have disappeared - they haven't! Just go up to the 'Search' box in the upper right of your Name Page tab and clear out the search term. The participants should reappear. If you've tried this and are still having trouble, please contact email@example.com so that we can take a look at your situation.