If you are using ADF 11g and you encounter this issue kindly check your ps_txn table. You can delete the records from this table and then you will see that this error will go away.
This table is used by ADFm internally to serialize user session state to database, so this table has to be monitored and appropriate grants have to be given to the database user so that it can create the database objects.
For more information kindly refer to this article by chris muir.
PS_TXN