[Python] Odoo 18 on Windows: UnicodeDecodeError: 'utf-8' codec can't decode byte 0xe7 on...

I'm setting up a development environment for Odoo 18 on a Windows machine. I've cloned the repository, created a virtual environment (venv), and successfully installed all dependencies from the requirements.txt file.

However, when I try to start the Odoo server for the first time using the command below, the process fails with a UnicodeDecodeError.

Command executed:

PowerShell

(venv) PS D:\tarefas\trarefa_kaue_1\teste\odoo> python odoo-bin -r odoo -w 123
Full Error (Traceback):


2025-08-16 04:07:47,493 14676 INFO ? odoo: Odoo version 18.0
2025-08-16 04:07:47,493 14676 INFO ? odoo: addons paths: ['D:\\tarefas\\trarefa_kaue_1\\teste\\odoo\\odoo\\addons', 'c:\\users\\kauen\\appdata\\local\\openerp s.a\\odoo\\addons\\18.0', 'd:\\tarefas\\trarefa_kaue_1\\teste\\odoo\\odoo\\addons', 'd:\\tarefas\\trarefa_kaue_1\\teste\\odoo\\addons']
2025-08-16 04:07:47,493 14676 INFO ? odoo: database: odoo@default:default
2025-08-16 04:07:50,148 14676 INFO ? odoo.addons.base.models.ir_actions_report: You need Wkhtmltopdf to print a pdf version of the reports.
2025-08-16 04:07:50,152 14676 INFO ? odoo.addons.base.models.ir_actions_report: You need Wkhtmltoimage to generate images from html.
2025-08-16 04:07:52,396 14676 INFO ? odoo.service.server: HTTP service (werkzeug) running on kaue_martins.intelbras.local:8069
Exception in thread odoo.service.cron.cron0:
Traceback (most recent call last):
File "C:\Python312\Lib\threading.py", line 1075, in _bootstrap_inner
self.run()
File "C:\Python312\Lib\threading.py", line 1012, in run
self._target(*self._args, **self._kwargs)
File "D:\tarefas\trarefa_kaue_1\teste\odoo\odoo\service\server.py", line 541, in target
self.cron_thread(i)
File "D:\tarefas\trarefa_kaue_1\teste\odoo\odoo\service\server.py", line 522, in cron_thread
with contextlib.closing(conn.cursor()) as cr:
File "D:\tarefas\trarefa_kaue_1\teste\odoo\odoo\sql_db.py", line 799, in cursor
return Cursor(self.__pool, self.__dbname, self.__dsn)
File "D:\tarefas\trarefa_kaue_1\teste\odoo\odoo\sql_db.py", line 288, in __init__
self._cnx = pool.borrow(dsn)
File "D:\tarefas\trarefa_kaue_1\teste\odoo\venv\Lib\site-packages\decorator.py", line 232, in fun
return caller(func, *(extras + args), **kw)
File "D:\tarefas\trarefa_kaue_1\teste\odoo\odoo\tools\func.py", line 97, in locked
return func(inst, *args, **kwargs)
File "D:\tarefas\trarefa_kaue_1\teste\odoo\odoo\sql_db.py", line 726, in borrow
result = psycopg2.connect(
File "D:\tarefas\trarefa_kaue_1\teste\odoo\venv\Lib\site-packages\psycopg2\__init__.py", line 122, in connect
conn = _connect(dsn, connection_factory=connection_factory, **kwasync)
UnicodeDecodeError: 'utf-8' codec can't decode byte 0xe7 in position 78: invalid continuation byte


My Environment Details:

OS: Windows 11

Odoo: Version 18.0

Python: Version 3.12 (installed at C:\Python312)

PostgreSQL: Version 15

What I've investigated so far:

The traceback indicates the error occurs during the psycopg2.connect call, which is the library used to connect to PostgreSQL.

The UnicodeDecodeError with byte 0xe7 suggests there's a special character (likely ç in a latin-1 or windows-1252 encoding) somewhere in the connection string that is not UTF-8 encoded.

I have checked the parameters I passed on the command line (-r odoo and -w 123), and they do not contain any special characters.

The PostgreSQL database was initialized with UTF-8 encoding.

My suspicion is that the problem might be in a Windows environment variable or in the Odoo configuration file (odoo.conf), which might be read with an incorrect encoding (like windows-1252) instead of UTF-8.

My questions are:

Where do Odoo or psycopg2 on Windows look for connection information besides the command-line parameters?

What is the most likely cause for this UnicodeDecodeError in this scenario, and how can I fix it?

Thanks for any help!

Continue reading...