I am now working on the E-Business Suite Release 12 upgrade project. The login page broke after integrating the R12 development system with Oracle Single Sign-On. We recieved 'HTTP 500 Internal Server Error'. Furthermore, the local login page (/OA_HTML/AppsLocalLogin.jsp) too was not getting rendered.
This certainly seemed to a java servlet initialization problem in the Oracle OC4J. I noticed the following errors in the $INST_TOP/logs/ora/10.1.3/j2ee/oacore/oacore_default_group_1/application.log
Error initializing servletjava.lang.NoClassDefFoundError: Could not initialize class oracle.apps.fnd.profiles.Profiles
html: chain failed javax.servlet.ServletException at com.evermind[Oracle Containers for J2EE 10g
I could not a direct answer after searching the Oracle Support website. I was able to better understand the problem after reviewing the $INST_TOP/logs/ora/10.1.3/opmn/oacore_default_group_1/oacorestd.err logfile.
Exception in static block of jtf.cache.CacheManager. Stack trace is: oracle.apps.jtf.base.resources.FrameworkException: IAS Cache initialization failed.
The problem has something to do with the Java Cache. I went ahead and disabled the cache mechanism by setting the parameter LONG_RUNNING_JVM to false in the $INST_TOP/ora/10.1.3/j2ee/oacore/config/oc4j.properties and this solved the problem.I will update this article once I know the root cause why the Cache failed to initialize after the SSO integration.