TypeError: 'NoneType' object is not iterable

Dear all, I got some error after trying to make ‘Quotation’ from Opportunity, especially it happens only when I choose Lead and then convert. Also, get item from Opportunity in Quotation has the same problem. Here below is the error feedback from ERPNext.

Traceback (most recent call last):
File “/home/frappe/frappe-bench/apps/frappe/frappe/app.py”, line 56, in application
response = frappe.handler.handle()
File “/home/frappe/frappe-bench/apps/frappe/frappe/handler.py”, line 21, in handle
data = execute_cmd(cmd)
File “/home/frappe/frappe-bench/apps/frappe/frappe/handler.py”, line 52, in execute_cmd
return frappe.call(method, **frappe.form_dict)
File “/home/frappe/frappe-bench/apps/frappe/frappe/init.py”, line 922, in call
return fn(*args, **newargs)
File “/home/frappe/frappe-bench/apps/frappe/frappe/model/mapper.py”, line 37, in map_docs
target_doc = method(src, target_doc)
File “/home/frappe/frappe-bench/apps/erpnext/erpnext/crm/doctype/opportunity/opportunity.py”, line 234, in make_quotation
}, target_doc, set_missing_values)
File “/home/frappe/frappe-bench/apps/frappe/frappe/model/mapper.py”, line 109, in get_mapped_doc
postprocess(source_doc, target_doc)
File “/home/frappe/frappe-bench/apps/erpnext/erpnext/crm/doctype/opportunity/opportunity.py”, line 214, in set_missing_values
quotation.run_method(“calculate_taxes_and_totals”)
File “/home/frappe/frappe-bench/apps/frappe/frappe/model/document.py”, line 666, in run_method
out = Document.hook(fn)(self, *args, **kwargs)
File “/home/frappe/frappe-bench/apps/frappe/frappe/model/document.py”, line 887, in composer
return composed(self, method, *args, **kwargs)
File “/home/frappe/frappe-bench/apps/frappe/frappe/model/document.py”, line 870, in runner
add_to_return_value(self, fn(self, *args, **kwargs))
File “/home/frappe/frappe-bench/apps/frappe/frappe/model/document.py”, line 660, in
fn = lambda self, *args, **kwargs: getattr(self, method)(*args, **kwargs)
File “/home/frappe/frappe-bench/apps/erpnext/erpnext/controllers/accounts_controller.py”, line 105, in calculate_taxes_and_totals
self.calculate_contribution()
File “/home/frappe/frappe-bench/apps/erpnext/erpnext/controllers/selling_controller.py”, line 138, in calculate_contribution
for sales_person in sales_team:
TypeError: ‘NoneType’ object is not iterable

Anybody please help me how to fix it.

Thank you so much in advance.

Best Regards,

@cipher

Can you share the version details of erpnext app? It seems that you’re using older version of erpnext