Click "Safari" on the menu bar. Select Preferences.
Select the Privacy tab. Under "Cookies and website data", make sure the bubble for "Always allow" is filled.
Click to open the menu in the top right. Select Preferences.
Select the Privacy tab. Under "Block cookies:", make sure the bubble for "Never" is filled.
Select customize in the upper right
Click settings on the dropdown menu
In the page that opens, scroll all the way to the bottom and select Show advanced settings
Scroll down and click on the Content settings button
in the window that pops up, make sure that Block thrid-party cookies and site data is unchecked