Since yesterday we receive errors when we create a purchase order.

Traceback (most recent call last):
  File "/home/odoo/src/odoo/11.0/odoo/http.py", line 653, in _handle_exception
    return super(JsonRequest, self)._handle_exception(exception)
  File "/home/odoo/src/odoo/11.0/odoo/http.py", line 312, in _handle_exception
    raise pycompat.reraise(type(exception), exception, sys.exc_info()[2])
  File "/home/odoo/src/odoo/11.0/odoo/tools/pycompat.py", line 87, in reraise
    raise value
  File "/home/odoo/src/odoo/11.0/odoo/http.py", line 695, in dispatch
    result = self._call_function(**self.params)
  File "/home/odoo/src/odoo/11.0/odoo/http.py", line 344, in _call_function
    return checked_call(self.db, *args, **kwargs)
  File "/home/odoo/src/odoo/11.0/odoo/service/model.py", line 97, in wrapper
    return f(dbname, *args, **kwargs)
  File "/home/odoo/src/odoo/11.0/odoo/http.py", line 337, in checked_call
    result = self.endpoint(*a, **kw)
  File "/home/odoo/src/odoo/11.0/odoo/http.py", line 939, in __call__
    return self.method(*args, **kw)
  File "/home/odoo/src/odoo/11.0/odoo/http.py", line 517, in response_wrap
    response = f(*args, **kw)
  File "/home/odoo/src/odoo/11.0/addons/web/controllers/main.py", line 934, in call_kw
    return self._call_kw(model, method, args, kwargs)
  File "/home/odoo/src/odoo/11.0/addons/web/controllers/main.py", line 926, in _call_kw
    return call_kw(request.env[model], method, args, kwargs)
  File "/home/odoo/src/odoo/11.0/odoo/api.py", line 687, in call_kw
    return call_kw_model(method, model, args, kwargs)
  File "/home/odoo/src/odoo/11.0/odoo/api.py", line 672, in call_kw_model
    result = method(recs, *args, **kwargs)
  File "/home/odoo/src/odoo/11.0/addons/base_automation/models/base_automation.py", line 210, in create
    action._process(action._filter_post(record))
  File "/home/odoo/src/odoo/11.0/addons/base_automation/models/base_automation.py", line 184, in _process
    self.action_server_id.with_context(**ctx).run()
  File "/home/odoo/src/odoo/11.0/odoo/addons/base/ir/ir_actions.py", line 573, in run
    res = func(action, eval_context=eval_context)
  File "/home/odoo/src/odoo/11.0/addons/mail/models/ir_actions.py", line 55, in run_action_email
    action.template_id.with_context(cleaned_ctx).send_mail(self._context.get('active_id'), force_send=False, raise_exception=False)
  File "/home/odoo/src/odoo/11.0/addons/mail/models/mail_template.py", line 544, in send_mail
    values = self.generate_email(res_id)
  File "/home/odoo/src/enterprise/11.0/l10n_mx_edi/models/mail_template.py", line 13, in generate_email
    res = super(MailTemplate, self).generate_email(res_ids, fields=fields)
  File "/home/odoo/src/odoo/11.0/addons/mail/models/mail_template.py", line 459, in generate_email
    res_ids_to_templates = self.get_email_template(res_ids)
  File "/home/odoo/src/odoo/11.0/addons/mail/models/mail_template.py", line 400, in get_email_template
    langs = self.render_template(self.lang, self.model, res_ids)
  File "/home/odoo/src/odoo/11.0/addons/mail/models/mail_template.py", line 357, in render_template
    records = self.env[model].browse(it for it in res_ids if it)  # filter to avoid browsing [None]
  File "/home/odoo/src/odoo/11.0/odoo/api.py", line 761, in __getitem__
    return self.registry[model_name]._browse((), self)
  File "/home/odoo/src/odoo/11.0/odoo/modules/registry.py", line 179, in __getitem__
    return self.models[model_name]
KeyError: False