This Application Will Be Blocked In A Future Java Security Update

When running a Java application, you get this message:

This application will be blocked in a future Java security update because the JAR file manifest does not contain the Permissions attribute.

This may be because Microsoft have released a patch that blocks older versions of Java (unless you specify not to block them in a GPO). It is more likely however, that you are getting a message stating that the application will be blocked because you have not specified the URL of the application in the Java Deployment Ruleset.