First, please visit http://www.adobe.com/software/flash/about to make sure your Flash software is up-to-date (an out-of-date Flash player will be blocked by Safari so this brief test is very important). It's been our experience that if it says "Flash out-of-date" it's best NOT to click that button, as it takes you to a Safari home page with no choices to update Flash; instead, go to http://get.adobe.com/flashplayer to download and install the latest version. Note that you must click the .dmg file that it downloads, to start the install. Finally, you must quit and restart Safari after Flash installs.
If the Flash plug-in was deactivated (upgrading to OSX Sierra causes this, among other things), you can activate it as follows:
- Open a page / tab to https://www.geni.com (you'll need this for step 7 below)
- Pull down the Safari menu and choose Preferences...
- click the Security button in the preferences header
- Make sure the checkbox labeled "Allow Plug-ins" is checked
- Click the button labeled "Plug-in Settings..." next to Allow Plug-ins
- Find Adobe Flash Player on the list on the left and turn on the checkbox next to it.
- In the main panel (on the right of the list) you should now see geni.com listed with an option to turn Flash on for our site -- select On
- Click Done and the red (x) to close Preferences, and then try again: https://www.geni.com/family-tree