Solution for 500 Internal server Error in R12

Error:
500 Internal Server Error

java.lang.NoClassDefFoundError
at oracle.apps.fnd.sso.AppsLoginRedirect.AppsSetting(AppsLoginRedirect.java:120)
at oracle.apps.fnd.sso.AppsLoginRedirect.init(AppsLoginRedirect.java:161)
at com.evermind[Oracle Containers for J2EE 10g (10.1.3.0.0)
].server.http.HttpApplication.loadServlet(HttpApplication.java:2231)
at com.evermind[Oracle Containers for J2EE 10g (10.1.3.0.0)
].server.http.HttpApplication.findServlet(HttpApplication.java:4617)
at com.evermind[Oracle Containers for J2EE 10g (10.1.3.0.0)
].server.http.HttpApplication.findServlet(HttpApplication.java:4541)
at com.evermind[Oracle Containers for J2EE 10g (10.1.3.0.0)
].server.http.HttpApplication.getRequestDispatcher(HttpApplication.java:2821)
at com.evermind[Oracle Containers for J2EE 10g (10.1.3.0.0)
].server.http.HttpRequestHandler.doProcessRequest(HttpRequestHandler.java:740)
at com.evermind[Oracle Containers for J2EE 10g (10.1.3.0.0)
].server.http.HttpRequestHandler.processRequest(HttpRequestHandler.java:451)
at com.evermind[Oracle Containers for J2EE 10g (10.1.3.0.0)
].server.http.AJPRequestHandler.run(AJPRequestHandler.java:299)
at com.evermind[Oracle Containers for J2EE 10g (10.1.3.0.0)
].server.http.AJPRequestHandler.run(AJPRequestHandler.java:187)


Solution:

Autoconfig

1) Bring down opmn services.
Path: /tst03/oracle/VIS/inst/apps/VIS_bkpsvr/admin/scripts>./adopmnctl.sh stop apps/apps

2) Verify no process is listening for s_java_object_cache_port value

3) Change s_java_object_cache_port on all the nodes in the context file

Path: /tst03/oracle/VIS/inst/apps/VIS_bkpsvr/appl/admin>vi VIS_bkpsvr.xml

Before:
12348

After:
12349

4) Run autoconfig on apps node.

Path: /tst03/oracle/VIS/inst/apps/VIS_bkpsvr/admin/scripts>./ adautocfg.sh

5) Start opmn services on apps node.

Path: /tst03/oracle/VIS/inst/apps/VIS_bkpsvr/admin/scripts>./adopmnctl.sh start apps/apps