Unable to launch application error message when trying to login as a teacher.

The “Unable to launch application” error message is caused by Java trying to pull down an update for the web start application unable to overwrite its cache. It can be resolved by clearing the Java cache and re-downloading the web start application.  For instructions on how to clear your Java cache please click here. (https://www.java.com/en/download/help/plugin_cache.xml)