FRM-40733 PL/SQL built in DBMS_error_code failed

On client side developer faced the below issue (11gR2 database) and requested for the investigations.

I got the below after research

A)

This can be a generic error for any application that exploits FORMS.

1. If at a particular point in time,the instance encountered an error 
• e.g. : ORA-3113 - end of file on communication channel or
• ORA-3114 - database connection lost or
• Some Internal ORA -600 error that leads to stoppage of any of the Background Processes... ( SMON, PMON ......)
• Then the form would have abruptly thrown the exception as its database connection thread to the kernel can no longer communicate to the DB kernel. At that point in time the form is capable of throwing any error message.
2. The above could be a one time occurrence because of some instance crashing
   or some other error at the instance level that may have causes this form
   to error out.

Solution
It's necessary to have a reproducible test-case to trap the exceptions. Otherwise, it might have been a one time event, which would be difficult to debug.

Check the database alert log file. Look for any ORA-600s or ORA-7445. If found, investigate separately with RDBMS technology support.



B) Check the properties of Form Block specially ORDER BY. There could be problem if you are using the subquery in order by. Optimizer may get issue.

In such case try below workaround:
Set hidden parameter_optimizer_cost_based_transfortmation to off :
--for session level
alter session set "_optimizer_cost_based_transfortmation" =off;

--for system level
alter system set "_optimizer_cost_based_transfortmation" =off;

C) Check the query sized used in the form, you may face the issue if the size exceeds 4K. 

D) Make sure that all of the database objects are valid which are being used in your Form.