Hi Dave,
Thank you so much for your help,
1 : this is an example robot file that will produce this error for me :
*** Settings ***
Library Selenium2Library
*** Test Case ***
Test Case 1
Open Browser https://www.google.com/ Firefox
Maximize Browser Window
Close Browser
2 : My OS and the version :
Microsoft Windows 10 Entreprise LTSC Version 10.0.17763 Build 17763
3 : My Python version :
Python 3.7
4 : My Python modules versions :
Package Version
async-generator 1.10
attrs 21.2.0
backports.cached-property 1.0.1
backports.entry-points-selectable 1.1.1
certifi 2021.10.8
cffi 1.15.0
charset-normalizer 2.0.9
colorama 0.4.4
configparser 5.2.0
coverage 6.2
crayons 0.4.0
cryptography 36.0.1
decorator 5.1.0
distlib 0.3.4
filelock 3.4.0
grpcio 1.43.0
grpcio-tools 1.43.0
h11 0.12.0
idna 3.3
importlib-metadata 4.9.0
jsonpath-rw 1.4.0
jsonpath-rw-ext 1.2.2
outcome 1.1.0
overrides 6.1.0
pbr 5.8.0
pip 21.3.1
platformdirs 2.4.0
pluggy 0.13.1
ply 3.11
protobuf 3.19.1
py 1.11.0
pycparser 2.21
pyOpenSSL 21.0.0
requests 2.26.0
robotframework 4.1.3
robotframework-assertion-engine 0.2.0
robotframework-browser 11.1.1
robotframework-jsonlibrary 0.3.1
robotframework-pythonlibcore 3.0.0
robotframework-requests 0.9.2
robotframework-selenium2library 3.0.0
robotframework-seleniumlibrary 5.1.3
selenium 4.1.0
setuptools 39.0.1
six 1.16.0
sniffio 1.2.0
sortedcontainers 2.4.0
tox 3.0.0
trio 0.19.0
trio-websocket 0.9.2
typing_extensions 4.0.1
typing-utils 0.1.0
urllib3 1.26.7
virtualenv 20.10.0
webdriver-manager 3.5.2
wrapt 1.13.3
wsproto 1.0.0
zipp 3.6.0
5 : My nodejs version :
v16.13.1
6 : for rfbrowser init, yes I dit it, there was no problem retourning
Thank you so much Dave 