I had to update my Java to the latest version, because of installing switches with FOS 7.2.1. I type the IP into my IE browser, get all the Java Applet installation pop-ups, get the log in pop-up, and the program starts, but it will not display the WebGUI window. Here is the last line from the Java Console:
log4j:WARN No appenders could be found for logger (com.brocade.wtcommon.access.AccessController). log4j:WARN Please initialize the log4j system properly.