Facebook Video Chat plugin no longer works on Mavericks After upgrading my Mac OS X 10.6.8 Snow Leopard to OS X 10.9 Mavericks, I've encountered a minor problem. The video chat plugin of Facebook no longer works. On the Facebook chat box, the video chat icon is no longer visible. I've tried uninstalling the plugin by removing the contents of ~/Library/Application Support/Facebook but I still haven't seen the video chat icon. 

I have installed/setup the video chat plugin of Facebook before and it was working well before the upgrade. I already installed Java on my system since it prompts to be installed after the upgrade. 

$ java -version
java version "1.6.0_65"
Java(TM) SE Runtime Environment (build 1.6.0_65-b14-462-11M4609)


So, any workaround for this? This is the first issue I've encountered on OS X Mavericks.
Perhaps you accidentally blocked a required plugin through Safari's new "power-saving" feature?

Go to Safari Preferences -> Security -> Check "Allow Plug-ins" and click "Manage Website Settings..." -> Make sure www.facebook.com is not blocked from any of the listed plugins.