What is your platform/Application Version?
Is this a new installation/ Upgrade/Cloned environment?
If not and it was working before, did anyone change anything in the configuration?
Is the issue only for the specific user/ for all?
At what point you are receiving this error?
I am using Oracle r12.1.3, and this issue is at overall application level (TEST INSTANCE), I have applied some profile option values for testing purpose.
In order to gather more details regarding the exception, First, right click into the error page and "View Source." Sometimes this will give you more detail into the exception. Secondly, enable the FND: Diagnostics system profile and bounce the middle tier instance. This should enable the Framework page to give you a "Details" link for a complete error stack.
Hope this helps,
Please also post other log files like
Oracle Application Server Diagnostic Tools and Log Files in Applications Release 12 (Doc ID 454178.1)