Error while selecting group by Item Groups in Sales Analytics


Out of nowhere I started getting this error: TypeError: unsupported operand type(s) for +: 'NoneType' and 'int'

whenever I select Item Groups in the Group By filter in Sales Analytics. What could have gone wrong?!

Here is the error details:

### App Versions
	"erpnext": "13.27.0",
	"frappe": "13.26.1"
### Route
query-report/Sales Analytics
### Trackeback
Traceback (most recent call last):
  File "apps/frappe/frappe/", line 69, in application
    response = frappe.api.handle()
  File "apps/frappe/frappe/", line 55, in handle
    return frappe.handler.handle()
  File "apps/frappe/frappe/", line 37, in handle
    data = execute_cmd(cmd)
  File "apps/frappe/frappe/", line 75, in execute_cmd
    return, **frappe.form_dict)
  File "apps/frappe/frappe/", line 1447, in call
    return fn(*args, **newargs)
  File "apps/frappe/frappe/", line 766, in wrapper_fn
    retval = fn(*args, **get_newargs(fn, kwargs))
  File "apps/frappe/frappe/desk/", line 254, in run
    result = generate_report_result(report, filters, user, custom_columns, is_tree, parent_field)
  File "apps/frappe/frappe/", line 766, in wrapper_fn
    retval = fn(*args, **get_newargs(fn, kwargs))
  File "apps/frappe/frappe/desk/", line 88, in generate_report_result
    res = get_report_result(report, filters) or []
  File "apps/frappe/frappe/desk/", line 69, in get_report_result
    res = report.execute_script_report(filters)
  File "apps/frappe/frappe/core/doctype/report/", line 146, in execute_script_report
    res = self.execute_module(filters)
  File "apps/frappe/frappe/core/doctype/report/", line 163, in execute_module
    return frappe.get_attr(method_name)(frappe._dict(filters))
  File "apps/erpnext/erpnext/selling/report/sales_analytics/", line 14, in execute
    return Analytics(filters).run()
  File "apps/erpnext/erpnext/selling/report/sales_analytics/", line 43, in run
  File "apps/erpnext/erpnext/selling/report/sales_analytics/", line 109, in get_data
  File "apps/erpnext/erpnext/selling/report/sales_analytics/", line 237, in get_sales_transactions_based_on_item_group
  File "apps/erpnext/erpnext/selling/report/sales_analytics/", line 381, in get_groups
    self.depth_map.setdefault(, self.depth_map.get(d.parent) + 1)
TypeError: unsupported operand type(s) for +: 'NoneType' and 'int'

### Request Data
	"type": "GET",
	"args": {
		"report_name": "Sales Analytics",
		"filters": "{\"tree_type\":\"Item Group\",\"doc_type\":\"Sales Invoice\",\"value_quantity\":\"Value\",\"from_date\":\"2022-01-01\",\"to_date\":\"2022-12-31\",\"company\":\"ASSET For Industrial & Energy Solutions LLC\",\"range\":\"Monthly\"}"
	"headers": {},
	"error_handlers": {},
	"url": "/api/method/"
### Response Data
	"exception": "TypeError: unsupported operand type(s) for +: 'NoneType' and 'int'"


Can you please help me with this error?