JRE 7 update 51 issue with tree applet in browsers
there is currently an issue with the recently released update 51 for Java 7 , this update includes two security changes designed to enhance authentication and
authorization for Rich Internet Applications (Applets and Web Start), the WebCenter Sites releases do not contain the permissions attribute defined in the Jar's Manifest, this is a requirement
from JRE 1.7 u 51, for more info see : https://blogs.oracle.com/java-platform-group/entry/new_security_requirements_for_rias
Development engineering is aware of the issue , it has been reported in defect 17993766 - PERMISSIONS ATTRIBUTE NOT DEFINED IN JARS MANIFEST
In case your environment is affected by this issue the available options are :