1. Install Java On Firefox

If, after installing Java for OS X 2014-001 and the latest version of Java 7 from Oracle, you want to disable Java 7 and re-enable the Apple-provided Java SE 6 web plug-in and Web Start functionality, follow these steps.

Note: You must be logged in as an administrator. If prompted for your administrator password after a command, enter it and then press the Return or Enter key.

When I updated Safari to v.12, I found out that Java no longer works. I installed the latest version of Java restarted my Mac and Safari. When I went to the Java test page I got the message 'Unsupported plug-in.' Mac OS X Yosemite (and the newer versions) are having a later version of Java Runtime (SE 8.0). However, Java Runtime is not backward compatible. So, even when the operating system have installed Java Runtime 8, it will NOT run apps that rely on Java Runtime 6.

1. Open Terminal, located in the Utilities folder.
2. Enter this command, then press the Return or Enter key:
   
3. Enter this command, then press the Return or Enter key:
   
4. Enter this command, then press the Return or Enter key:
   
5. To re-enable Java SE 6 Web Start, enter this command, then press the Return or Enter key:
   

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The following steps will undo the above commands and restore Java 7 in OS X Lion and later.

• Allowing Java Content on a Website 1. Launch the Firefox web browser. Click or double-click the.
• I already see you are running 10.6.7 'Snow Leopard', etc., but the version of Java and Firefox installed are big factors. Since you have an Intel platform, upgrade Firefox to version 4 for Mac. Secondly, see if you can go to Software Update found in the Apple menu, and update Java.

Install Java On Firefox

1. Disable Java SE 6 Web Start opening:
   • Enter this command, then press the Return or Enter key:
   • When prompted, enter your administrator password, then press the Return or Enter key.
2. Re-enable the Java 7 applet plug-in bydownloading and reinstalling the latest version of Oracle Java 7 JRE.