Hi Community,

I'm trying sending an invoice with the send and print button inside an invoice, so, when i click on send button. I get this error:

Error:
Odoo Server Error

Traceback (most recent call last):
  File "/odoo/odoo-server/odoo/http.py", line 656, in _handle_exception
    return super(JsonRequest, self)._handle_exception(exception)
  File "/odoo/odoo-server/odoo/http.py", line 314, in _handle_exception
    raise pycompat.reraise(type(exception), exception, sys.exc_info()[2])
  File "/odoo/odoo-server/odoo/tools/pycompat.py", line 87, in reraise
    raise value
  File "/odoo/odoo-server/odoo/http.py", line 698, in dispatch
    result = self._call_function(**self.params)
  File "/odoo/odoo-server/odoo/http.py", line 346, in _call_function
    return checked_call(self.db, *args, **kwargs)
  File "/odoo/odoo-server/odoo/service/model.py", line 97, in wrapper
    return f(dbname, *args, **kwargs)
  File "/odoo/odoo-server/odoo/http.py", line 339, in checked_call
    result = self.endpoint(*a, **kw)
  File "/odoo/odoo-server/odoo/http.py", line 941, in __call__
    return self.method(*args, **kw)
  File "/odoo/odoo-server/odoo/http.py", line 519, in response_wrap
    response = f(*args, **kw)
  File "/odoo/odoo-server/addons/web/controllers/main.py", line 966, in call_button
    action = self._call_kw(model, method, args, {})
  File "/odoo/odoo-server/addons/web/controllers/main.py", line 954, in _call_kw
    return call_kw(request.env[model], method, args, kwargs)
  File "/odoo/odoo-server/odoo/api.py", line 749, in call_kw
    return _call_kw_multi(method, model, args, kwargs)
  File "/odoo/odoo-server/odoo/api.py", line 736, in _call_kw_multi
    result = method(recs, *args, **kwargs)
  File "/odoo/odoo-server/addons/snailmail_account/wizard/account_invoice_send.py", line 75, in send_and_print_action
    res = super(AccountInvoiceSend, self).send_and_print_action()
  File "/odoo/odoo-server/addons/account/wizard/account_invoice_send.py", line 83, in send_and_print_action
    self._send_email()
  File "/odoo/odoo-server/addons/account/wizard/account_invoice_send.py", line 68, in _send_email
    self.composer_id.send_mail()
  File "/odoo/odoo-server/addons/mail/wizard/mail_compose_message.py", line 267, in send_mail
    ActiveModel.browse(res_id).message_post(**post_params)
  File "/odoo/odoo-server/addons/account_facturx/models/account_invoice.py", line 214, in message_post
    res = super(AccountInvoice, self).message_post(**kwargs)
  File "/odoo/odoo-server/addons/account/models/account_invoice.py", line 677, in message_post
    return super(AccountInvoice, self.with_context(mail_post_autofollow=True)).message_post(**kwargs)
  File "/odoo/odoo-server/addons/rating/models/mail_thread.py", line 14, in message_post
    message = super(MailThread, self).message_post(**kwargs)
  File "/odoo/odoo-server/addons/mail/models/mail_thread.py", line 2065, in message_post
    self._message_post_after_hook(new_message, values, model_description=model_description, mail_auto_delete=mail_auto_delete)
  File "/odoo/odoo-server/addons/mail_bot/models/mail_thread.py", line 12, in _message_post_after_hook
    return super(MailThread, self)._message_post_after_hook(message, values, model_description=model_description, mail_auto_delete=mail_auto_delete)
  File "/odoo/odoo-server/addons/mail/models/mail_thread.py", line 2087, in _message_post_after_hook
    mail_auto_delete=mail_auto_delete,
  File "/odoo/odoo-server/addons/mail/models/mail_message.py", line 1068, in _notify
    model_description=model_description, mail_auto_delete=mail_auto_delete)
  File "/odoo/odoo-server/addons/mail/models/mail_message.py", line 1148, in _notify_recipients
    self.env['res.partner']._notify(self, partner_email_rdata, record, force_send=force_send, send_after_commit=send_after_commit, model_description=model_description, mail_auto_delete=mail_auto_delete)
  File "/odoo/odoo-server/addons/mail/models/res_partner.py", line 126, in _notify
    recipients = self.env['mail.thread']._notify_classify_recipients_on_records(message, rdata, records=record)
  File "/odoo/odoo-server/addons/mail/models/mail_thread.py", line 792, in _notify_classify_recipients_on_records
    return records._notify_classify_recipients(message, recipient_data)
  File "/odoo/odoo-server/addons/mail/models/mail_thread.py", line 766, in _notify_classify_recipients
    groups = self._notify_get_groups(message, default_groups)
  File "/odoo/odoo-server/addons/account/models/account_invoice.py", line 991, in _notify_get_groups
    groups = super(AccountInvoice, self)._notify_get_groups(message, groups)
  File "/odoo/odoo-server/addons/portal/models/portal_mixin.py", line 85, in _notify_get_groups
    additional_params.update(customer.signup_get_auth_param()[customer.id])
AttributeError: 'res.partner' object has no attribute 'signup_get_auth_param'

Debugging the application, unninstaling unnecesary modules and 3rd party modules related to account i get the same error. For that i think the error is in account module from Odoo S.A., in other words, the account core module. 

Can you help me to fix it? 

Thank you!.