The data_key argument for one or more fields collides with another field's name or data_key argument.

[jmontanag]

I would like to know more about this error. Is it not possible to have same data_key for different fields ?

[lafrech]

• https://marshmallow.readthedocs.io/en/stable/upgrading.html#attribute-or-data-key-collision-triggers-an-exception
• #1008

[jmontanag]

Thank you for your response, add load_only=True works for me.