Error: 'Document' object is not iterable

quest.js:457 Traceback (most recent call last):
File “apps/frappe/frappe/app.py”, line 66, in application
response = frappe.api.handle()
File “apps/frappe/frappe/api.py”, line 54, in handle
return frappe.handler.handle()
File “apps/frappe/frappe/handler.py”, line 45, in handle
data = execute_cmd(cmd)
File “apps/frappe/frappe/handler.py”, line 83, in execute_cmd
return frappe.call(method, **frappe.form_dict)
File “apps/frappe/frappe/init.py”, line 1607, in call
return fn(*args, **newargs)
File “apps/frappe/frappe/model/workflow.py”, line 135, in apply_workflow
doc.submit()
File “apps/frappe/frappe/model/document.py”, line 1005, in submit
return self._submit()
File “apps/frappe/frappe/model/document.py”, line 984, in _submit
return self.save()
File “apps/frappe/frappe/model/document.py”, line 305, in save
return self._save(*args, **kwargs)
File “apps/frappe/frappe/model/document.py”, line 356, in _save
self.run_post_save_methods()
File “apps/frappe/frappe/model/document.py”, line 1085, in run_post_save_methods
self.run_method(“on_submit”)
File “apps/frappe/frappe/model/document.py”, line 914, in run_method
out = Document.hook(fn)(self, *args, **kwargs)
File “apps/frappe/frappe/model/document.py”, line 1264, in composer
return composed(self, method, *args, **kwargs)
File “apps/frappe/frappe/model/document.py”, line 1246, in runner
add_to_return_value(self, fn(self, *args, **kwargs))
File “apps/frappe/frappe/model/document.py”, line 911, in fn
return method_object(*args, **kwargs)
File “apps/jewellery_erpnext/jewellery_erpnext/gurukrupa_exports/doctype/cad_order_form/cad_order_form.py”, line 12, in on_submit
create_cad_orders(self)
File “apps/jewellery_erpnext/jewellery_erpnext/gurukrupa_exports/doctype/cad_order_form/cad_order_form.py”, line 31, in create_cad_orders
docname = make_cad_order(row.name, parent_doc = self)
File “apps/jewellery_erpnext/jewellery_erpnext/gurukrupa_exports/doctype/cad_order_form/cad_order_form.py”, line 64, in make_cad_order
doc.save()
File “apps/frappe/frappe/model/document.py”, line 305, in save
return self._save(*args, **kwargs)
File “apps/frappe/frappe/model/document.py”, line 327, in _save
return self.insert()
File “apps/frappe/frappe/model/document.py”, line 251, in insert
self._validate_links()
File “apps/frappe/frappe/model/document.py”, line 873, in _validate_links
invalid_links, cancelled_links = self.get_invalid_links()
File “apps/frappe/frappe/model/base_document.py”, line 748, in get_invalid_links
values = _dict(name=frappe.db.get_value(doctype, docname, “name”, cache=True))
File “apps/frappe/frappe/database/database.py”, line 496, in get_value
result = self.get_values(
File “apps/frappe/frappe/database/database.py”, line 570, in get_values
out = self._get_value_for_many_names(
File “apps/frappe/frappe/database/database.py”, line 840, in _get_value_for_many_names
return self.get_all(
File “apps/frappe/frappe/database/database.py”, line 724, in get_all
return frappe.get_all(*args, **kwargs)
File “apps/frappe/frappe/init.py”, line 1924, in get_all
return get_list(doctype, *args, **kwargs)
File “apps/frappe/frappe/init.py”, line 1896, in get_list
return frappe.model.db_query.DatabaseQuery(doctype).execute(*args, **kwargs)
File “apps/frappe/frappe/model/db_query.py”, line 202, in execute
result = self.build_and_run()
File “apps/frappe/frappe/model/db_query.py”, line 217, in build_and_run
args = self.prepare_args()
File “apps/frappe/frappe/model/db_query.py”, line 255, in prepare_args
self.set_optional_columns()
File “apps/frappe/frappe/model/db_query.py”, line 552, in set_optional_columns
for element in each:
TypeError: ‘Document’ object is not iterable