You are currently using CAST from within a web browser.
We strongly recommend that you download it and run CAST's stand-alone version instead.
CAST and browsers
CAST was originally designed to run with within a web browser using web standards (HTML, CSS and Javascript) to display static text and images and for navigations. However these were not (and are still not) suitable for showing the complex dynamic and interactive diagrams that are a core part of CAST, so an alternative solution was found using a browser plugin called "applets" that allowed small Java programs to be embedded in pages.
All browsers showed these Java applets until recently, but support has now been dropped by Google Chrome, Microsoft's Edge browser does not support them, and Firefox is intending to drop support at the end of 2016.
As a result, the old "web browser" CAST is only likely to properly display the summary and video pages of e-books that have them in the future. To get the "full" CAST experience including the interactive and dynamic pages, you will need to download CAST (from the Download tab that appeared when CAST was started) and run it as a stand-alone Java program from there.
Java
You will need to install Java support on your computer, both to run the stand-alone version of CAST and also to get access to the interactive diagrams in the browser-based version.You should go to Oracle's main Java web site and make sure that you have the most recent version of Java installed.
Browser-based version of CAST
There are no known problems when using CAST (over the internet or from a downloaded copy) with the current releases of...
However we strongly recommend that you download CAST and run the stand-alone version — it will be needed some time in the future.