This usually means that either you've disabled or restricted Java in the browser or that your Java installation has somehow become corrupted. I'm not sure why, but I've been hearing from more users with corrupted Java installations lately.
The good news is that this is usually easy to fix and you have options. First, if you have other browsers installed, you might try loading the planner using them to see if anything is different. It might be worth it to verify your Java installation
at java.com. If that doesn't help, it's pretty easy to uninstall Java and reinstall it to make sure your installation is clean.
Below are steps to uninstall and reinstall Java on Windows systems:
1.Close all web browser windows
2.Go to the windows start menu, then go to Control Panel\Programs\Programs and Features\uninstall a program.
3.In the list of installed programs, click on the name column to sort the list of programs by name.
4.Scroll down to the J’s. and then uninstall any versions of Java present on your system.
5.Once everything is removed, follow the instructions at java.com to install the latest version of java.
Finally, if for some reason you can't get Java in the browser to work, you can always download the standalone version
of the planner.