The problem isn't on our end and IMO shouldn't require us to lower our security settings or add exceptions.
The applet appears to be signed by Avocent Huntsville Corporation already.
The problem is that the JAR manifest is missing the Permissions Attribute. See https://www.java.com/en/download/help/java_blocked.xml.
Any timeframe when this bug will be fixed?
It's been broken since Java 7u51 was released on 2014-01-14.
Oracle gave plenty of notice ahead of that release about this security functionality.