Hello,

There is a field named picking_type_id in the model purchase.order which comes from the module named purchase_stock and to get default value for this field a function is also defined in the code.

In your case, the field might not get the value from the function. As it is required field and value is not entered, you are getting this error message. So just make the field visible in the view and give a value for the field and try. Also you can check and trace why it doesn't get the value.

Also check and ensure that if there is custom ad-dons in the instance, they are not causing ant trouble.

Thank you for your help.

But after I have a fresh new install, this problem not occur.

Still don't know why.

Thank you