# "SessionNotCreatedException: Message: None" under Python 3.12.0

**URL:** <https://forum.robotframework.org/t/sessionnotcreatedexception-message-none-under-python-3-12-0/7293>\
**Category:** SeleniumLibrary\
**Created:** [15 May 2024 09:19 UTC](https://forum.robotframework.org/t/sessionnotcreatedexception-message-none-under-python-3-12-0/7293 "2024-05-15T09:19:24Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![pakitoh00](https://avatars.discourse-cdn.com/v4/letter/p/cc9497/32.png) [@pakitoh00](https://forum.robotframework.org/u/pakitoh00)\
**Post date:** [15 May 2024 09:19 UTC](https://forum.robotframework.org/t/sessionnotcreatedexception-message-none-under-python-3-12-0/7293/1 "2024-05-15T09:19:25Z")

</div>

Hello, I have updated my python from version 3.9.9 to version 3.12.0 and with it all my Robotframework dependencies on my Windows machine.  
When launching “Open Browser” to launch my tests on a private server I am receiving the error **“SessionNotCreatedException: Message: None”** without any explanation beyond this simple message. I’m not sure if this is a version incompatibility as I’m not getting any help from the error message.

How I launch my tests running in Python 3.9.9:

```python
${chrome_options}=	Evaluate	sys.modules['selenium.webdriver'].ChromeOptions()	sys, selenium.webdriver										
Call Method	${chrome_options}	add_argument	--start-maximized										
Call Method	${chrome_options}	add_argument	--disable-notifications					
${prefs}	Create Dictionary	download.default_directory=${downloadDefaultDirectory}	useAutomationExtension=${FALSE}	download.prompt_for_download=${FALSE}	safebrowsing.enabled=${TRUE}	download.directory_upgrade=${TRUE}
Call Method	${chrome_options}	add_experimental_option	prefs	${prefs}									
${desired_capabilities}=	Create Dictionary	browserName=${browser}	userName=${userName}	token=${token}	pacAlias=${pacAlias}	video=true				
Open Browser	${url}	remote_url=${s_url}	options=${chrome_options}	desired_capabilities=${desired_capabilities}

```

Dependency list:

````python
attrs 23.2.0
autopep8 2.1.0
beautifulsoup4 4.12.3
cached-property 1.5.2
certifi 2024.2.2
cffi 1.16.0
chardet 5.2.0
charset-normalizer 3.3.2
click 8.1.7
colorama 0.4.6
comtypes 1.4.2
convertdate 2.4.0
cryptography 42.0.7
decorator 5.1.1
defusedxml 0.7.1
dnspython 2.6.1
docutils 0.21.2
et-xmlfile 1.1.0
exchangelib 5.4.0
fire 0.6.0
fonttools 4.51.0
fpdf2 2.7.8
furl 2.1.3
graphviz 0.20.3
h11 0.14.0
hijri-converter 2.3.1
holidays 0.48
htmldocx 0.0.6
idna 3.7
importlib_metadata 7.1.0
isodate 0.6.1
java-access-bridge-wrapper 1.2.0
jsonpath-ng 1.6.1
jsonschema 4.22.0
jsonschema-specifications 2023.12.1
korean-lunar-calendar 0.3.1
lxml 5.2.2
more-itertools 10.2.0
mss 9.0.1
netsuitesdk 2.21.3
notifiers 1.3.3
O365 2.0.34
oauthlib 3.2.2
openpyxl 3.1.2
orderedmultidict 1.0.1
outcome 1.3.0.post0
packaging 24.0
pdfminer.six 20231228
pendulum 3.0.0
pillow 10.3.0
pip 24.0
platformdirs 4.2.2
ply 3.11
psutil 5.9.8
pycodestyle 2.11.1
pycparser 2.22
Pygments 2.18.0
PyJWT 2.8.0
PyMeeus 0.5.12
pynput-robocorp-fork 5.0.0
pyotp 2.9.0
pypdf 4.2.0
pyperclip 1.8.2
Pypubsub 4.0.3
PySocks 1.7.1
pyspnego 0.10.2
python-dateutil 2.9.0.post0
python-docx 1.1.2
python-dotenv 1.0.1
pytz 2024.1
pytz-deprecation-shim 0.1.0.post0
pywin32 306
pywinauto 0.6.8
PyYAML 6.0.1
referencing 0.35.1
requests 2.31.0
requests-file 2.0.0
requests-ntlm 1.2.0
requests-oauthlib 2.0.0
requests-toolbelt 1.0.0
robocorp-storage 1.0.4
robotframework 7.0
robotframework-excellentlibrary 1.0.0
robotframework-pythonlibcore 4.4.1
robotframework-requests 0.9.7
robotframework-ride 2.0.8.1
robotframework-sapguilibrary 1.1
robotframework-seleniumlibrary 6.3.0
robotframework-seleniumtestability 2.1.0
rpaframework-core 11.3.2
rpaframework-pdf 7.3.2
rpaframework-windows 7.5.1
rpds-py 0.18.1
selenium 4.20.0
setuptools 69.5.1
simple-salesforce 1.12.6
six 1.16.0
smartsheet-python-sdk 3.0.2
sniffio 1.3.1
sortedcontainers 2.4.0
soupsieve 2.5
sspilib 0.1.0
stringcase 1.2.0
tenacity 8.3.0
termcolor 2.4.0
time-machine 2.14.1
trio 0.25.0
trio-websocket 0.11.1
tweepy 4.14.0
typing_extensions 4.11.0
tzdata 2024.1
tzlocal 5.2
uiautomation 2.0.18
urllib3 2.2.1
validators 0.28.1
webdriver-manager 4.0.1
wrapt 1.16.0
wsproto 1.2.0
wxPython 4.2.1
xlrd 2.0.1
xlutils 2.0.0
xlwt 1.3.0
zeep 4.2.1
zipp 3.18.1
```
````

---

<div class="post-metadata">

**Author:** ![Noordsestern](https://dub1.discourse-cdn.com/flex005/user_avatar/forum.robotframework.org/noordsestern/32/4270_2.png) [@Noordsestern](https://forum.robotframework.org/u/Noordsestern)\
**Post date:** [12 June 2024 20:47 UTC](https://forum.robotframework.org/t/sessionnotcreatedexception-message-none-under-python-3-12-0/7293/2 "2024-06-12T20:47:00Z")

</div>

Hi Jose,

sorry for the delay.

The error message is coming from Selenium and is indeed not telling much. After your post [SeleniumLibrary 6.4.0 got released](https://github.com/robotframework/SeleniumLibrary/releases/tag/v6.4.0) mentioning that selenium had rearranged some settings and SeleniumLibrary fixed those for `Open Browser` keyword (see [issue 1900](https://github.com/robotframework/SeleniumLibrary/issues/1900)). Maybe the new version already fixes the issue?

Furthermore, if it is a problem with the python version, SeleniumLibrary states on [its readme](https://github.com/robotframework/SeleniumLibrary?tab=readme-ov-file#id6) that officially only Python up to 3.11 is supported. Maybe try downgrading to 3.11 then.

Regards,  
Markus