I took a deep breath and upgraded my MacBook to Mountain Lion yesterday. Things are going pretty well, but a website I use regularly has a complicated security arrangement that uses several Java applets. I noticed that the site had not shut down all its components. A bit of investigation revealed that I needed a new version of Java (version 7 build 40). This process created several Java fail events.
First, the download is 150 megabytes. For a browser plugin that was supposed to solve problems. Second, once downloaded, the install requires exiting Safari (and, presumably, any other browser). Once installed (thankfully a fairly painless process), Java launches the default browser and asks if you want to check to be sure you have the most recent version of Java installed.
Pro-tip: before you do anything else, go to History / Reopen All Windows From Last Session. Otherwise you may lose them.
When I clicked the button to check Java, I got the message “inactive plugin” with no additional explanation. I checked Safari preferences. Nope, Java was fully enabled. Tried the Java version check again. Same message. Accidentally clicked the “inactive plugin” message and saw this:
You read that correctly. Checking the Java version requires … Java. Wow. I guess that’s one way of making sure Java is really there, but it’s kind of sketchy from where I’m sitting.