Click on “Safari" in the upper left side of your screen. In the dropdown menu that appears, click “Clear History.”
In the same dropdown menu as above, click on “Preferences.” In the window that appears, click on the “Security” tab. “Allow Plug-ins” should be checked. Then, select “Plug-in Settings.” Make sure “Adobe Flash Player” is checked. Also make sure “When visiting other websites” is on. Click “Done.”
Within “Preferences,” select the “Privacy" tab. Click the button “Manage Website Data….” In the window that appears, select “Remove All” and then select “Done.”