Account Receivable Summary

I got errors as following:

Traceback (most recent call last):
File “/home/accounting/frappe-bench/apps/frappe/frappe/app.py”, line 56, in application
response = frappe.handler.handle()
File “/home/accounting/frappe-bench/apps/frappe/frappe/handler.py”, line 21, in handle
data = execute_cmd(cmd)
File “/home/accounting/frappe-bench/apps/frappe/frappe/handler.py”, line 52, in execute_cmd
return frappe.call(method, **frappe.form_dict)
File “/home/accounting/frappe-bench/apps/frappe/frappe/init.py”, line 922, in call
return fn(*args, **newargs)
File “/home/accounting/frappe-bench/apps/frappe/frappe/desk/query_report.py”, line 95, in run
res = frappe.get_attr(method_name)(frappe._dict(filters))
File “/home/accounting/frappe-bench/apps/erpnext/erpnext/accounts/report/accounts_receivable_summary/accounts_receivable_summary.py”, line 133, in execute
return AccountsReceivableSummary(filters).run(args)
File “/home/accounting/frappe-bench/apps/erpnext/erpnext/accounts/report/accounts_receivable_summary/accounts_receivable_summary.py”, line 12, in run
return self.get_columns(party_naming_by, args), self.get_data(party_naming_by, args)
File “/home/accounting/frappe-bench/apps/erpnext/erpnext/accounts/report/accounts_receivable_summary/accounts_receivable_summary.py”, line 52, in get_data
partywise_total = self.get_partywise_total(party_naming_by, args)
File “/home/accounting/frappe-bench/apps/erpnext/erpnext/accounts/report/accounts_receivable_summary/accounts_receivable_summary.py”, line 91, in get_partywise_total
party_total[d.party][k] += d.get(k, 0)
TypeError: unsupported operand type(s) for +=: ‘NoneType’ and ‘NoneType’

ERPNext: v8.5.4 (master)
Frappe Framework: v8.5.7 (master)