EBS SSO fnderror-"oracle.apps.fnd.ext.common.server.FndSsoException: Unknown exception. Please contact your System Administrator."

Environment Details:  Oracle E-Business Suite 12.1.3 has been integrated with Oracle Access Manager 11.1.1.5 for SSO.

Issue:  SSO setup has been enabled and working fine. After the OAM SSO authentication user see an error saying "Unknown exception. Please contact your System Administrator". The following exception has been thrown in the Accessgate server logs.

SEVERE: FATAL error while instantiating internal connection..aborting the request
weblogic.jdbc.extensions.PoolLimitSQLException: weblogic.common.resourcepool.ResourceLimitException: No resources currently available in pool dsfin02_ebs_tempdev to allocate to applications, please increase the size of the pool and retry..
    at weblogic.jdbc.common.internal.JDBCUtil.wrapAndThrowResourceException(JDBCUtil.java:252)
    at weblogic.jdbc.common.internal.RmiDataSource.getPoolConnection(RmiDataSource.java:352)
    at weblogic.jdbc.common.internal.RmiDataSource.getConnection(RmiDataSource.java:369)
    at oracle.apps.fnd.ext.jdbc.connection.DatasourceAppsConnection.getConnection(DatasourceAppsConnection.java:53)
    at oracle.apps.fnd.ext.jdbc.utils.DataSourceImpl.getConnection(DataSourceImpl.java:54)
    at oracle.apps.fnd.ext.common.server.AppsHttpServletRequestWrapper.(Unknown Source)
    at oracle.apps.fnd.ext.common.server.FndSsoFilter.doFilter(Unknown Source)
    at weblogic.servlet.internal.WebAppServletContext$ServletInvocationAction.wrapRun(WebAppServletContext.java:3715)
    at weblogic.servlet.internal.WebAppServletContext$ServletInvocationAction.run(WebAppServletContext.java:3681)
    at weblogic.security.acl.internal.AuthenticatedSubject.doAs(AuthenticatedSubject.java:321)
    at weblogic.security.service.SecurityManager.runAs(SecurityManager.java:120)
    at weblogic.servlet.internal.WebAppServletContext.securedExecute(WebAppServletContext.java:2277)
    at weblogic.servlet.internal.WebAppServletContext.execute(WebAppServletContext.java:2183)
    at weblogic.servlet.internal.ServletRequestImpl.run(ServletRequestImpl.java:1454)
    at weblogic.work.ExecuteThread.run(ExecuteThread.java:178)
Apr 5, 2012 10:49:11 AM oracle.apps.fnd.ext.common.server.AppsHttpServletRequestWrapper getLangCode:

:

:

:

:

Apr 5, 2012 10:49:11 AM oracle.apps.fnd.ext.common.server.FndSsoFilter doFilter
WARNING: FndSsoFilter::doFilter()-- error encountered
oracle.apps.fnd.ext.common.server.FndSsoException: Unknown exception. Please contact your System Administrator.
    at oracle.apps.fnd.ext.common.server.AppsHttpServletRequestWrapper.(Unknown Source)
    at oracle.apps.fnd.ext.common.server.FndSsoFilter.doFilter(Unknown Source)
    at weblogic.servlet.internal.WebAppServletContext$ServletInvocationAction.wrapRun(WebAppServletContext.java:3715)
    at weblogic.servlet.internal.WebAppServletContext$ServletInvocationAction.run(WebAppServletContext.java:3681)
    at weblogic.security.acl.internal.AuthenticatedSubject.doAs(AuthenticatedSubject.java:321)
    at weblogic.security.service.SecurityManager.runAs(SecurityManager.java:120)
    at weblogic.servlet.internal.WebAppServletContext.securedExecute(WebAppServletContext.java:2277)
    at weblogic.servlet.internal.WebAppServletContext.execute(WebAppServletContext.java:2183)
    at weblogic.servlet.internal.ServletRequestImpl.run(ServletRequestImpl.java:1454)
    at weblogic.work.ExecuteThread.run(ExecuteThread.java:178)
Caused by: weblogic.jdbc.extensions.PoolLimitSQLException: weblogic.common.resourcepool.ResourceLimitException: No resources currently available in pool dsfin02_ebs_tempdev to allocate to applications, please increase the size of the pool and retry..
    at weblogic.jdbc.common.internal.JDBCUtil.wrapAndThrowResourceException(JDBCUtil.java:252)
    at weblogic.jdbc.common.internal.RmiDataSource.getPoolConnection(RmiDataSource.java:352)
    at weblogic.jdbc.common.internal.RmiDataSource.getConnection(RmiDataSource.java:369)
    at oracle.apps.fnd.ext.jdbc.connection.DatasourceAppsConnection.getConnection(DatasourceAppsConnection.java:53)
    at oracle.apps.fnd.ext.jdbc.utils.DataSourceImpl.getConnection(DataSourceImpl.java:54)
    ... 10 more
Apr 5, 2012 10:49:11 AM oracle.apps.fnd.ext.common.server.FndSsoFilter doFilter
WARNING: FndSsoFilter::doFilter()-- error message

Root Cause for this Error: FND ERROR occurs due to the AccessGate connection pool limitation. During the error all the allocated connection pool's were utilized. 

Solution:  Increase the connection pool limit as below shown and restart the weblogic server to this setting become effective. During the restart the all the utilized connection will be reset-ed to '0'.