Cannot Access Oracle Application Forms After Cloning

After cloaning the instance. sometimes users will not be able to launch any forms.

The error.log shows:
[error] mod_plsql: /pls/oracle/fnd_icx_launch.launch HTTP-503 ORA-12538
access_log shows:
"GET /pls/kmapat/fnd_icx_launch.launch?resp_app=SYSADMIN&resp_key=SYSTEM_ADMINISTRATOR&secgrp_key=STANDARD&start_func=FND_FNDCPQCR_SYS&other_params= HTTP/1.1" 503 316

We frequently see this sort of issue where users cannot access forms after a clone.
One of the things about the Cloning Process is that the Logs associated with the Clone Process will not show issues with environment, file or data corruption issues in the Clone Logs. The Logs do not capture any environment type issues that occur after a clone. You may be able to Clone an Instance 1000 times without any issue, but then you may encounter an issue on the 1001st clone,
which will not show up in the Logs because it is an environment, file or data corruption issue.
Solution

1. On the Target Instance which is having the problems after the clone, start comparing the size of the file systems between Target and Source.

du -sk prodappl (source)

du -sk testappl (target)

Do this for all base directories involved.
Then once a difference is found, then zero down to a particular directory and then the corrupted files.

2. If there is no difference between the Source and Target Instance, then
- Copy over the $JAVA_TOP, $ORACLE_HOME/forms and $OA_HTML/bin from the source to the target instance.

- Run AutoConfig or the Clone Steps once again to complete after copying the Files over.

- Retest the issue.