Forms :: Unable To Insert Records

I am getting this error FRM 40508 in inserting data to any table through forms 11g.

eg:

my test table having two columns : id and name

i wrote a simple insert statement insert into test values (:id, :name);
commit;

when i run the application and insert the values, it shows the above error.

when I use the display errors , it shows that there is a violation : ora - 00001 (duplicate values)

however, there is no such value in the database.

The same scenario is repeating with every table I have.

I thing more, when I use the commit_form only without using any manual insert statement, then everything goes well. But with manual insert it all fails.