Either clear all cache click buttons <Ctrl> + <Shift> + <Delete> brings you to Clear Browsing Data page, which clears all of your settings for all sites that you visit.
Or for a more surgical method go to your browsers “Settings” > Content Settings > Cookies >brings you to “All Cookies and site locations”. From here search on race or raceqs.com. click to delete this file. Log back into RaceQs and your tracks will be visible during replay.