### App Versions
```
{
	"crm": "2.0.0-dev",
	"erpnext": "15.33.0",
	"frappe": "15.38.0",
	"gameplan": "0.0.1",
	"hrms": "15.27.0",
	"payments": "0.0.1",
	"print_designer": "1.2.0",
	"taakd_app": "0.0.1",
	"tldraw_whiteboard": "0.0.1"
}
```
### Route
```
Form/Applicant Invitation/new-applicant-invitation-mmokyjytvp
```
### Traceback
```
Traceback (most recent call last):
  File "apps/frappe/frappe/app.py", line 114, in application
    response = frappe.api.handle(request)
  File "apps/frappe/frappe/api/__init__.py", line 49, in handle
    data = endpoint(**arguments)
  File "apps/frappe/frappe/api/v1.py", line 36, in handle_rpc_call
    return frappe.handler.handle()
  File "apps/frappe/frappe/handler.py", line 49, in handle
    data = execute_cmd(cmd)
  File "apps/frappe/frappe/handler.py", line 85, in execute_cmd
    return frappe.call(method, **frappe.form_dict)
  File "apps/frappe/frappe/__init__.py", line 1768, in call
    return fn(*args, **newargs)
  File "apps/frappe/frappe/utils/typing_validations.py", line 31, in wrapper
    return func(*args, **kwargs)
  File "apps/frappe/frappe/desk/form/save.py", line 39, in savedocs
    doc.save()
  File "apps/frappe/frappe/model/document.py", line 337, in save
    return self._save(*args, **kwargs)
  File "apps/frappe/frappe/model/document.py", line 359, in _save
    return self.insert()
  File "apps/frappe/frappe/model/document.py", line 291, in insert
    self.run_before_save_methods()
  File "apps/frappe/frappe/model/document.py", line 1092, in run_before_save_methods
    self.run_method("before_save")
  File "apps/frappe/frappe/model/document.py", line 962, in run_method
    out = Document.hook(fn)(self, *args, **kwargs)
  File "apps/frappe/frappe/model/document.py", line 1322, in composer
    return composed(self, method, *args, **kwargs)
  File "apps/frappe/frappe/model/document.py", line 1304, in runner
    add_to_return_value(self, fn(self, *args, **kwargs))
  File "apps/frappe/frappe/model/document.py", line 959, in fn
    return method_object(*args, **kwargs)
  File "apps/taakd_app/taakd_app/taakd_app/doctype/applicant_invitation/applicant_invitation.py", line 14, in before_save
    self.sum_total_price()
  File "apps/taakd_app/taakd_app/taakd_app/doctype/applicant_invitation/applicant_invitation.py", line 234, in sum_total_price
    self.total_price  =  self.sum_other_services_price() + self.get_item_price(self.package)
TypeError: unsupported operand type(s) for +: 'NoneType' and 'float'

```
### Request Data
```
{
	"type": "POST",
	"args": {
		"doc": "{\"docstatus\":0,\"doctype\":\"Applicant Invitation\",\"name\":\"new-applicant-invitation-mmokyjytvp\",\"__islocal\":1,\"__unsaved\":1,\"owner\":\"company4@gmail.com\",\"payd_from\":\"Company\",\"language\":\"en\",\"cumulative_invoice\":1,\"other_services\":[],\"email\":\"abdoalsofi576@gmail.com\",\"first_name\":\"abdo\",\"last_name\":\"sofi\",\"_full_name\":\"abdo  sofi\",\"company_email\":\"company4@gmail.com\",\"company_name\":\"Company 3\",\"package\":\"باقة الوظائف العادية\",\"file_image\":\"/files/Developer activity-bro.png\",\"description\":\"العادية\",\"package_price\":500,\"other_services_price\":15,\"total_price\":515,\"creation\":\"\",\"modified_by\":\"company4@gmail.com\",\"modified\":\"\",\"idx\":0}",
		"action": "Save"
	},
	"btn": {
		"jQuery37006695061617070371": {
			"events": {
				"click": [
					{
						"type": "click",
						"origType": "click",
						"guid": 599,
						"namespace": ""
					}
				]
			}
		}
	},
	"freeze": true,
	"headers": {},
	"error_handlers": {},
	"url": "/api/method/frappe.desk.form.save.savedocs",
	"request_id": null
}
```
### Response Data
```
{
	"exception": "TypeError: unsupported operand type(s) for +: 'NoneType' and 'float'",
	"exc_type": "TypeError",
	"_exc_source": "taakd_app (app)"
}
```