How to resolve this error - " One of the documents you are trying to access has been deleted, please try refreshing"? in Odoo v8?

Whenever I try to create an employee record in Human Resources, when I click Save, the above error occurs.

I checked in the database for any kind of ir-regularities and found that I have attached the screenshot.

As in the database error, the Autoincrement ID has been skipped as I have noticed. Anyone with a clear insight on this, kindly suggest with what can be done. It would really grateful. Thanks

Solution

Ok I am answering the question,

There was a custom module which I was not aware of(other than my custom module) and that was installed. UNinstalling it removed the error.