macOS X 10.11 EL Capitan - macOS 10.12 Sierra - Running Safari v10

 First make sure your operating system and browser are fully up to date.

 Open Safari and Click on Safari>Preferences.

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 Choose the Security option and select Plug-in Settings…

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 Click on the Java item, Hold Alt (or Option), click the drop down menu next to the, and unselect Run in Safe Mode.

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 Click on Trust, click Done. Then close the Safari preferences window.

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