500 Internal server error
 

When i am accessing oracle 12i application so receiving the following 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)

I can't access application at all.
Regards,
Fawad