Java and Mac OS X 10.9
Keeping current with Java, you may find some websites start to fail to work. First verify you have the latest Java from http://www.java.com/
Next the Edit Site List preference found in the Apple menu -> System preferences -> Java after installing that Java, lets you control which websites
are able to run on Java that otherwise might think they have the wrong security. Be careful to only allow sites on that list you actually trust: