We're facing a persistent RPC_ERROR on our Odoo 18 Enterprise staging server during the "Create Invoice" action from the "Create Invoices" wizard (`sale.advance.payment.inv`). This is the traceback:

(psycopg2.ProgrammingError: can't adapt type 'res.partner' 

...see full traceback below...)

**Key points:**

- The error occurs when using the "Create Invoices" button on a sales order.

- We are on Odoo 18 Enterprise, latest build, no custom code running (all custom modules uninstalled, server restarted, still persists).

- Error also happens after restoring database and running on fresh staging.

**Traceback (full):**

Traceback (most recent call last):
  File "/home/odoo/src/odoo/odoo/http.py", line 2122, in _transactioning
    return service_model.retrying(func, env=self.env)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/odoo/src/odoo/odoo/service/model.py", line 156, in retrying
    result = func()
             ^^^^^^
  File "/home/odoo/src/odoo/odoo/http.py", line 2089, in _serve_ir_http
    response = self.dispatcher.dispatch(rule.endpoint, args)
               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/odoo/src/odoo/odoo/http.py", line 2337, in dispatch
    result = self.request.registry['ir.http']._dispatch(endpoint)
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/odoo/src/odoo/odoo/addons/base/models/ir_http.py", line 333, in _dispatch
    result = endpoint(**request.params)
             ^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/odoo/src/odoo/odoo/http.py", line 754, in route_wrapper
    result = endpoint(self, *args, **params_ok)
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/odoo/src/odoo/addons/web/controllers/dataset.py", line 42, in call_button
    action = call_kw(request.env[model], method, args, kwargs)
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/odoo/src/odoo/odoo/api.py", line 533, in call_kw
    result = getattr(recs, name)(*args, **kwargs)
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/odoo/src/odoo/addons/sale/wizard/sale_make_invoice_advance.py", line 136, in create_invoices
    invoices = self._create_invoices(self.sale_order_ids)
               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/odoo/src/enterprise/industry_fsm_sale/wizard/sale_make_invoice_advance.py", line 11, in _create_invoices
    invoices = super()._create_invoices(sale_orders)
               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/odoo/src/enterprise/sale_timesheet_enterprise/wizard/sale_make_invoice_advance.py", line 42, in _create_invoices
    return super()._create_invoices(sale_orders)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/odoo/src/odoo/addons/sale_timesheet/wizard/sale_make_invoice_advance.py", line 51, in _create_invoices
    return super()._create_invoices(sale_orders)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/odoo/src/enterprise/sale_subscription/wizard/sale_make_invoice_advance.py", line 13, in _create_invoices
    return super(SaleAdvancePaymentInv, self)._create_invoices(sale_orders)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/odoo/src/odoo/addons/sale/wizard/sale_make_invoice_advance.py", line 170, in _create_invoices
    invoice = self.env['account.move'].sudo().create(
              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "<decorator-gen-283>", line 2, in create
  File "/home/odoo/src/odoo/odoo/api.py", line 495, in _model_create_multi
    return create(self, [arg])
           ^^^^^^^^^^^^^^^^^^^
  File "/home/odoo/src/odoo/addons/purchase/models/account_invoice.py", line 167, in create
    moves = super(AccountMove, self).create(vals_list)
            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "<decorator-gen-144>", line 2, in create
  File "/home/odoo/src/odoo/odoo/api.py", line 496, in _model_create_multi
    return create(self, arg)
           ^^^^^^^^^^^^^^^^^
  File "/home/odoo/src/odoo/addons/account/models/account_move.py", line 3193, in create
    moves = super().create(vals_list)
            ^^^^^^^^^^^^^^^^^^^^^^^^^
  File "<decorator-gen-50>", line 2, in create
  File "/home/odoo/src/odoo/odoo/api.py", line 496, in _model_create_multi
    return create(self, arg)
           ^^^^^^^^^^^^^^^^^
  File "/home/odoo/src/odoo/addons/mail/models/mail_thread.py", line 278, in create
    threads = super(MailThread, self).create(vals_list)
              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "<decorator-gen-0>", line 2, in create
  File "/home/odoo/src/odoo/odoo/api.py", line 496, in _model_create_multi
    return create(self, arg)
           ^^^^^^^^^^^^^^^^^
  File "/home/odoo/src/odoo/odoo/models.py", line 5017, in create
    records = self._create(data_list)
              ^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/odoo/src/odoo/odoo/models.py", line 5201, in _create
    cr.execute(SQL(
  File "/home/odoo/src/odoo/odoo/sql_db.py", line 354, in execute
    res = self._obj.execute(query, params)
          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3/dist-packages/psycopg2/extensions.py", line 113, in getquoted
    pobjs = [adapt(o) for o in self._seq]
             ^^^^^^^^
psycopg2.ProgrammingError: can't adapt type 'res.partner'

**Request:**

- What could be causing this error?

- Is this related to data integrity, an internal bug, or a known issue with partner record assignment in Odoo 18?

- Any steps to debug or hotfix?

Thanks for your support.