I have a custom module in which i want to import some of the updated data but getting an error

Unknown error during import: : 'field1' at row 2 Resolve other errors first

I am getting this error in some of the fields not all.

Below are the type and description and parameters of the field in which i am getting this error:-

field1 = fields.Many2one(comodel_name="ab", string="Field1", required=False, )
field2 = fields.Many2one(comodel_name="bc", string="Field2", required=False, )
field3 = fields.Char('Field3', size=30, required=True)
field4 = fields.Char('Field4', size=30)
field5 = fields.Char('Field5', size=30, required=True)