Login page is Blank in R12

Hi,

This is the application.log of the oacore.

12/05/22 12:55:36.680 html: oracle.apps.fnd.security.LeakDetectionFilter.initialized:1337671536680
12/05/22 12:55:36.680 html: LeakSetting:
        global:true,session:false,aggressive:false,stderr:false,appslog:false,corelog:false
        ignoring:null
12/05/22 12:55:36.890 html: chain failed
javax.servlet.ServletException: java.lang.RuntimeException: Unable to create user session. Please contact your System Administrator.
        at com.evermind[Oracle Containers for J2EE 10g (10.1.3.5.0) ].server.http.EvermindPageContext.handlePageThrowable(EvermindPageContext.java:899)
        at com.evermind[Oracle Containers for J2EE 10g (10.1.3.5.0) ].server.http.EvermindPageContext.handlePageException(EvermindPageContext.java:816)
        at _AppsLocalLogin._jspService(_AppsLocalLogin.java:303)
        at com.orionserver[Oracle Containers for J2EE 10g (10.1.3.5.0) ].http.OrionHttpJspPage.service(OrionHttpJspPage.java:59)