Make sure you have the latest version of JSwipe and that your phone’s operating system is up-to-date. If both of those things are up to date then try force quitting the app and relaunching it. If the issue persists, try deleting and reinstalling the app. To reinstall, just delete the app from your phone and download it again. As long as you don't delete your account, your messages and matches will be restored when you log back into the app.