Hello Simran,
This is because ,If you are not providing a value for an FK, OutSystems will check if the FK is mandatory or not. If it is mandatory, OutSystems will provide a default value: 0. Assuming the entity Person has an identifier Auto-number, their ids start at 1, hence the error from database
Check that you are passing the correct FK
Thanks and Regards,
Akshay Deshpande