Java is not working with Safari 6.0.3.

Have you updated to the latest version of Java? There seem to have been quite a few updates recently because of the security issues - there was one released last week, I believe.

Apple barred Java from running on Macs in order to safeguard users by blocking Java 7 Update 11 and adding it to the banned list in XProtect.

This was the second time in two weeks that Apple had blocked Oracle's code from running on Macs. The threat was so serious that the U.S. Department of Homeland Security had recommended that all Java 7 users disable or uninstall the software until a patch was issued. This time Java is blocked through Apple's XProtect anti-malware feature.

Java has come under fire as the means by which hackers have been able to gain control of computers. In April 2012 more than 600,000 Macs were reported to have been infected with a Flashback Trojan horse that was being installed on people's computers with the help of Java exploits. Then in August Macs were again at risk due to a flaw in Java, this time around, there was good news for Mac users: Thanks to changes Apple has made, most of us were safe from the threat.

Unwilling to leave its customers open to potential threats Apple decided it's safer to block Java entirely.

In order to block older versions of Flash, Apple has updated its "Xprotect.plist" file so that any versions that come before the current one (version 11.6.602.171) cannot be used on a Mac. Users who have older versions of Flash installed will be greeted with an alert that says "Blocked plug-in," and Safari will prompt the user to update to a newer version.

Macs running OS X Snow Leopard and beyond are affected.

UPDATE for those running Lion or Mountain Lion:

Oracle on Friday February 1 released a new version reportedly addressing vulnerabilities seen with the last build.

Apple disabled Java 7 through the OS X XProtect anti-malware system, requiring users to have at least version "1.7.0_10-b19" installed on their Macs. The release dated February 1 carries the designation "1.7.0_13-b20," meeting Apple's requirements.

Oracle "strongly recommends" applying the CPU fixes as soon as possible, saying that the latest Critical Patch Update contains 50 new security fixes across all Jave SE products.

Update for Snow Leopard users:

Apple issued update 12 for Java for OS 10.6:

http://support.apple.com/kb/DL1573

Note: On systems that have not already installed Java for Mac OS X 10.6 update 9 or later, this update will configure web browsers to not automatically run Java applets. Java applets may be re-enabled by clicking the region labeled "Inactive plug-in" on a web page. If no applets have been run for an extended period of time, the Java web plug-in will deactivate.

If, after installing Java for OS X 2013-002 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:

http://support.apple.com/kb/HT5559?viewlocale=en_US

Further update:

Apple issued this Java related security update No. 13 on February 19:

http://support.apple.com/kb/HT5666

and Update No. 14 on March 4: http://support.apple.com/kb/DL1573

http://support.apple.com/kb/HT5677

You should also read this:

https://support.apple.com/kb/HT5672

The standard recommendation is for users to turn off Java except when they have to use it on known and trusted websites (like their bank). Javascript, which is unrelated despite the name, can be left on.

Further useful comment in this article:

http://www.macworld.co.uk/macsoftware/news/?newsid=3435007&olo=email

Under either OSX 10.8.3 or 10.7.5, Java 7-17 runs under Firefox 19.02.

Under either OSX 10.8.3 or 10.7.5, Java 7-17 does not run under Safari 6.0.3.

Under either OSX 10.8.3 or 10.7.5, Java 7-17 does not run under Chrome 25.x (Chrome is 32 bit, Java is 64 bit only).

I was experiencing the same thing in Safari 6.0.3. It worked fine under Firefox.

By some odd reason, the update disabled the Java plug-in under Safari and the inline link to activate it was never being displayed.

1. I had to uninstall the plug-in. How do I uninstall Java 7 for my Mac?

2. Reset all website notification warnings. Safari 6 (OS X Mountain Lion): Reset Safari

3. Reinstall it. java.com: Java + You

4. Visit Oracle's Java test site. How do I test whether Java is working on my computer?

Only then the "Activate Plug-in" inline link finally appeared.

I'm not sure which one of these steps exacltly did the trick, but this was the way I made it work again.

Hope it helps.

I don't have Java installed on my systems, so I'm a bit sketchy on updating it.

I think Apple have a version they keep updated (which is on their Software Updates page ( http://support.apple.com/downloads/ - page 2).

Also Oracle issue updates their version. All very confusing, to me at least.

In System Preferences do you have a Java Preference Pane? If so, click on that to see if it offers any updates.

Also, in your Applications folder do you have an app called Java Preferences. If so, launch that and see if any updates are offered.

It seems that XProtect got recently updated (maybe by the 10.8.3 OSX Update?) and is now blocking current-version Java:

# ls -l /System/Library/CoreServices/CoreTypes.bundle/Contents/Resources/XProtect.meta. plist

-rw-r--r-- 1 root wheel 755 Mar 23 10:20 /System/Library/CoreServices/CoreTypes.bundle/Contents/Resources/XProtect.meta. plist

Checking the file, I found

<key>com.oracle.java.JavaAppletPlugin</key>

<dict>

<key>MinimumPlugInBundleVersion</key>

<string>1.7.17.02</string>

</dict>

I'm not sure, but I do remember that one of the late-January Apple blockage for Java consisted in grabbing then-current Update 11's version, then adding one to the final number so that none of the current Java plugins would work. (Basically, disabled 'till Oracle releases a new version). I wouldn't be surprised if Update 17's version is 1.7.17.01 and that's why it won't work.

Thing is, I did edit the file manually to 1.7.16.02, saved, quit/restarted safari ... and it *still* doesn't work. Maybe iTunes is still using the Safari process?

Ummm... scratch that. Even with 1.7.17.02 on XProtect, it will work but after visiting the Oracle's Java site and clicking on the "inactive plugin" inline link.

Rogerio's steps 1, 3 and 4 are what I did to reenable the Java plugin. Resetting website warnings isn't needed.

I found modifying a value of MinimumPlugInBundleVersion to 1.7.0_17 solves this;

my modification is..

# vi /System/Library/CoreServices/CoreTypes.bundle/Contents/Resources/XProtect.meta. plist

...SNIP...

<dict>

<key>10</key>

<dict>

<key>com.macromedia.Flash Player.plugin</key>

<dict>

<key>MinimumPlugInBundleVersion</key>

<string>11.6.602.171</string>

</dict>

<key>com.oracle.java.JavaAppletPlugin</key>

<dict>

<key>MinimumPlugInBundleVersion</key>

<string>1.7.0_17</string>

</dict>

</dict>

</dict>

...SNIP...

Please note that this modification might cause further defects on your mac.

4. Visit Oracle's Java test site. How do I test whether Java is working on my computer?

That fixed it for me - was very strange - it was workign fine on another system and in FireFox - and after uninstall, reinstall, deleteing prefs, resetting Safari, reboot, etc - finally went to the link above and it said inactive plugin - clicked on that - got it reactivated and now works fine.

The site that I use which has a java applet was designed for use with windows so on the Mac it is a tad flaky.

This worked for me too, tried on 3 machines now. Problem ws that not much really happened, when trying to verify or run applets. Following the link I got the inactive plugin. Click and there it went. Thanks!!!

Matt, your suggestion helped me greatly when I experienced exactly the same problem after installing Java 7 Update 21, last June 18.

Apparently, the plug-in is disabled by default, you are not prompted to choose whether to run any applet in Safari or any other browser and you are led to think there is something wrong with your installation or Java version.

The plug-in test works around the problem by triggering the inactive plug-in and making it work normally.

To all Java users: remember that when you access a Java site, you are warned that some applets might be insecure. If you allow them to run, Safari might eventually block them anyway, because the applets are not signed or are known to have caused trouble. If you still wish to run them, do this:

1. Go to the Safari menu and select Preferences.

2. Click on the Security icon.

3. Make sure that the "Enable Java Script" and "Allow Java" options are checked.

4. Click on the "Manage Website Settings" button.

5. Make sure to choose "Allow Always" from the dropdown menu in the window that appears near the name of the site where the applets reside. If you only choose "Allow", some applets will not run.

Again, remember that using Java these days may pose a security threat. Whenever that happens, Apple will update the OS and disable Java.