this causes logging inside applets to fail with the following exception:

Unexpected exception
java.security.AccessControlException: access denied ("java.lang.RuntimePermission" "accessClassInPackage.sun.reflect")
at java.security.AccessControlContext.checkPermission(Unknown Source)
at java.security.AccessController.checkPermission(Unknown Source)
at java.lang.SecurityManager.checkPermission(Unknown Source)
at java.lang.SecurityManager.checkPackageAccess(Unknown Source)
at sun.plugin2.applet.SecurityManagerHelper.checkPackageAccessHelper(Unknown Source)
at sun.plugin2.applet.AWTAppletSecurityManager.checkPackageAccess(Unknown Source)
at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at sun.plugin2.applet.Plugin2ClassLoader.loadClass0(Unknown Source)
at sun.plugin2.applet.Plugin2ClassLoader.loadClass(Unknown Source)
at sun.plugin2.applet.Plugin2ClassLoader.loadClass0(Unknown Source)
at sun.plugin2.applet.Plugin2ClassLoader.loadClass(Unknown Source)
at sun.plugin2.applet.Plugin2ClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at ch.qos.logback.classic.spi.PackagingDataCalculator.<clinit>(PackagingDataCalculator.java:42)
at ch.qos.logback.classic.spi.ThrowableProxy.getPackagingDataCalculator(ThrowableProxy.java:135)
...

using sun* classes may also cause problems when using a different VM!?