Error loading key rules resource file:

I deployed on TEST LINUX env, the extensions that I wrote. However, now when I start the server, I get the following error.

2009-10-05 14:15:06,434 INFO [com.percussion.ActionSets] An action set could not be loaded because of an error and will be skipped. com.percussion.extension.PSExtensionException: The ExtensionHandler handler could not initialize the Java extension: java.lang.NullPointerException.

After this error, the server shuts down with the following message in server.log:

14:21:21,933 INFO [Server] A non-recoverable error has been encountered. The server is shutting down.
14:21:21,933 INFO [Server] An unexpected error was encountered. java.lang.RuntimeException: Error loading key rules resource file: The ExtensionHandler handler could not initialize the Java extension: java.lang.NullPointerException.
14:21:21,936 WARN [PSAppServlet] Server did not initialize
14:21:28,940 INFO [EARDeployer] Started J2EE application: file:/Rhythmyx/AppServer/server/rx/deploy/rxapp.ear/
14:21:29,037 INFO [Http11Protocol] Starting Coyote HTTP/1.1 on http-0.0.0.0-9992
14:21:29,256 INFO [ChannelSocket] JK: ajp13 listening on /0.0.0.0:9998
14:21:29,274 INFO [JkMain] Jk running ID=0 time=0/31 config=null
14:21:29,441 INFO [Server] JBoss (MX MicroKernel) [4.0.3 (build: CVSTag=JBoss_4_0_3 date=200510042324)] Started in 1m:19s:782ms

thanks
Manvinder