In R12, when attempting to log in to EBS using HTTP://HOST.DOMAIN:PORT/,the following error occurs.

ERROR500 Internal Server Errorjava.lang.NoClassDefFoundError atoracle.apps.fnd.sso.AppsLoginRedirect.AppsSetting(AppsLoginRedirect.java:126) atoracle.apps.fnd.sso.AppsLoginRedirect.init(AppsLoginRedirect.java:170) at com.evermind[OracleContainers for J2EE 10g (10.1.3.0.0)
STEPSThe issue can be reproduced at will with the following steps:1. Clone existing R12 Environment2. Log-in to EBS using URL HTTP://HOST.DOMAIN:PORT/
BUSINESS IMPACTThe issue has the following business impact:Due to this issue, users cannot access/use the Cloned environment.

CauseThe issue is caused by the following setup: Incorrect set-up of the Distributed Caching, port:12377 is not available.
JDBC Buffers in Oracle Application: -This note outlines the issue that you encounter:If some JVMs out of many are not servicing requests and generating"java.lang.NoClassDefFoundError" errors. Disabling Distributed JVM caching would eliminate thisfrom being the cause of the problem.
In the customers instance, when you access the environment the following occurs1) Since Port 12377 is not available, Distributed Caching is unable to copy the class across toother jvm's and you get the error"500 Internal Server Errorjava.lang.NoClassDefFoundError"
Note:Disabling Distributed JVM Cache is achieved by changing "LONG_RUNNING_JVM=" from "true" to "false" in the oc4j.properties. This is controlled by AutoConfig parameter "s_long_running_jvm".

Solution
To implement the solution, please execute the following steps:

Solution 1

1. You can disable the use of "Distributed JVM cache" by disabling LONG_RUNNING_JVM- set oc4j.properties: ==> LONG_RUNNING_JVM= to "false"
Note: not usually recommended

Solution 2

1. Assign an available port for "Distributed JVM cache" by using the following steps
a) Set the correct port in your Context File -> parameter "s_java_object_cache_port"
2. Run Autoconfig on all Middle Tiers
3. Make sure your System Profile "JTF_DIST_CACHE_PORT" has the same port specified
4. Retest the issue.
5. Migrate the solution as appropriate to other environments.