Check to make sure you have the extension enabled in your browser.

In Google Chrome, navigate to the menu icon (≡) in the top right corner of the window. Click on it, then choose "More Tools", and then choose "Extensions". This should open a new window in Chrome.

In this new window, find an extension called NoClickjack. Make sure the Extension is enabled by clicking the "Enable" check box which is found to the right of the extension's name.

(An example of the extension disabled.)

Once enabled, you should see NoClickjack's blue shield icon in the top right corner of your browser.