Apple is blocking (http://support.apple.com/kb/HT5655) all un-updated version of the Flash Player plug-in for Safari due to security reasons. If the version of Adobe Flash plug-in you are using is out of date, you may see the message, “Blocked plug-in”, “Flash Security Alert” or “Flash out-of-date” when attempting to view Flash content in Safari.
In order to use Adobe Flash you need to update to a later version:
1. Click the Download Flash button.
2. Safari opens Adobe Flash Player installer page on the Adobe website.
3. Click the Download now button on the Adobe website to download the latest Adobe Flash Player installer.
4. After the download completes, open the downloaded disk image (usually located in your Downloads folder) if it does not open automatically.
5. In the window that appears, open the installer and follow the onscreen instructions.