Selenium 3.4.0 Unable to find matching capabilities

[jricardo27]

OS: Ubuntu
Selenium Version: 3.4.0
Browser: Firefox 45
Geckodriver: 0.16.0

Hi, After updating to Selenium 3.4.0 it can't start Firefox:

File "/root/venv/3.5/lib/python3.5/site-packages/selenium/webdriver/firefox/webdriver.py", line 152, in __init__
    keep_alive=True)
  File "/root/venv/3.5/lib/python3.5/site-packages/selenium/webdriver/remote/webdriver.py", line 98, in __init__
    self.start_session(desired_capabilities, browser_profile)
  File "/root/venv/3.5/lib/python3.5/site-packages/selenium/webdriver/remote/webdriver.py", line 185, in start_session
    response = self.execute(Command.NEW_SESSION, parameters)
  File "/root/venv/3.5/lib/python3.5/site-packages/selenium/webdriver/remote/webdriver.py", line 249, in execute
    self.error_handler.check_response(response)
  File "/root/venv/3.5/lib/python3.5/site-packages/selenium/webdriver/remote/errorhandler.py", line 194, in check_response
    raise exception_class(message, screen, stacktrace)
selenium.common.exceptions.WebDriverException: Message: Unable to find a matching set of capabilities

--------
Using Firefox 45 due to click not working on newer versions (mozilla/geckodriver#322)
--------

[cgoldberg]

Can this be reproduced on the newest Firefox nightly build?
Firefox 45 isn't expected to work with the newest versions of selenium (3.4.0) and geckodriver (0.16.0). Support for geckodriver 0.16 is best in Firefox 52.0.3 and onwards.

see:
https://github.com/mozilla/geckodriver#supported-firefoxen

[jricardo27]

It seems to work ok (Selenium 3.40 + Geckodriver 0.16.0 + Firefox 53.0).

Even the issue with the click (mozilla/geckodriver#322) seems to be working now.

Thanks for the advice.

[Nagasaki45]

I'm experiencing the same issue with

OS: arch linux
Python: 3.6
Selenium: 3.4.0
Geckodriver: 0.16.0
Firefox: 53.0

py.test failure

selenium.common.exceptions.WebDriverException: Message: Unable to find a matching set of capabilities

env/lib/python3.6/site-packages/selenium/webdriver/remote/errorhandler.py:194: WebDriverException

[mfin]

Same platform and stack as @Nagasaki45, same issue.

[AutomatedTester]

This bug will remain closed until we can get a high quality bug report. Me too comments don't really add value

[mfin]

@AutomatedTester I'd gladly help, but this is the only info I get. How can I gather more information about the issue?

[Petterrolvag]

Hi, I got the same error on my Windows 10 PC. I got rid of the error by installing firefox and reverting to previous geckodriver (geckodriver-v0.15.0-win64).

[AutomatedTester]

Unfortunately no one has given steps to reproduce. This is clearly more than just driver=webdriver.Firefox() issue.

We can't do anything until proper steps to reproduce are given as documented in Contributing.md

Selenium tree tests being run in Python 3.6.1 and are passing. I ran 4 to show session startup.

dburns in ~/development/selenium/py on master λ tox -c py/tox.ini -r -e py36-marionette -v
using tox.ini: /Users/dburns/development/selenium/py/tox.ini
using tox-2.3.1 from /usr/local/lib/python2.7/site-packages/tox/__init__.pyc
GLOB sdist-make: /Users/dburns/development/selenium/py/setup.py
  /Users/dburns/development/selenium/py$ /usr/local/opt/python/bin/python2.7 /Users/dburns/development/selenium/py/setup.py sdist --formats=zip --dist-dir /Users/dburns/development/selenium/py/.tox/dist >/Users/dburns/development/selenium/py/.tox/log/tox-0.log
py36-marionette recreate: /Users/dburns/development/selenium/py/.tox/py36-marionette
  /Users/dburns/development/selenium/py/.tox$ /usr/local/opt/python/bin/python2.7 -m virtualenv --python /usr/local/bin/python3.6 py36-marionette >/Users/dburns/development/selenium/py/.tox/py36-marionette/log/py36-marionette-0.log
py36-marionette installdeps: pytest==3.0.3, pytest-instafail==0.3.0, pytest-mock==1.5.0, pytest-xdist==1.15
  /Users/dburns/development/selenium/py$ /Users/dburns/development/selenium/py/.tox/py36-marionette/bin/pip install -v --no-index --find-links=../third_party/py pytest==3.0.3 pytest-instafail==0.3.0 pytest-mock==1.5.0 pytest-xdist==1.15 >/Users/dburns/development/selenium/py/.tox/py36-marionette/log/py36-marionette-1.log
py36-marionette inst: /Users/dburns/development/selenium/py/.tox/dist/selenium-3.4.0.zip
  /Users/dburns/development/selenium/py$ /Users/dburns/development/selenium/py/.tox/py36-marionette/bin/pip install -v --no-index --find-links=../third_party/py /Users/dburns/development/selenium/py/.tox/dist/selenium-3.4.0.zip >/Users/dburns/development/selenium/py/.tox/py36-marionette/log/py36-marionette-2.log
  /Users/dburns/development/selenium/py$ /Users/dburns/development/selenium/py/.tox/py36-marionette/bin/pip freeze >/Users/dburns/development/selenium/py/.tox/py36-marionette/log/py36-marionette-3.log
py36-marionette installed: apipkg==1.4,appdirs==1.4.3,execnet==1.4.1,packaging==16.8,py==1.4.32,pyparsing==2.2.0,pytest==3.0.3,pytest-instafail==0.3.0,pytest-mock==1.5.0,pytest-xdist==1.15.0,selenium==3.4.0,six==1.10.0
py36-marionette runtests: PYTHONHASHSEED='1420169364'
py36-marionette runtests: commands[0] | py.test -n=auto --driver=Marionette
  /Users/dburns/development/selenium/py$ /Users/dburns/development/selenium/py/.tox/py36-marionette/bin/py.test -n=auto --driver=Marionette
=================================================== test session starts ====================================================
platform darwin -- Python 3.6.1, pytest-3.0.3, py-1.4.32, pluggy-0.4.0
rootdir: /Users/dburns/development/selenium/py, inifile: setup.cfg
plugins: xdist-1.15.0, mock-1.5.0, instafail-0.3.0
gw0 [605] / gw1 [605] / gw2 [605] / gw3 [605]
scheduling tests via LoadScheduling
....^CERROR: KEYBOARDINTERRUPT

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! KeyboardInterrupt !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
to show a full traceback on KeyboardInterrupt use --fulltrace
/usr/local/Cellar/python3/3.6.1/Frameworks/Python.framework/Versions/3.6/lib/python3.6/threading.py:299: KeyboardInterrupt
================================================ 4 passed in 12.21 seconds =================================================
ERROR: keyboardinterrupt

[mfin]

@AutomatedTester actually, for me it's exactly that, driver = webdriver.Firefox() issue.

#!/usr/bin/env python3

from selenium import webdriver

driver = webdriver.Firefox()
driver.get('https://google.com')

Traceback (most recent call last):
  File "test2.py", line 5, in <module>
    driver = webdriver.Firefox()
  File "/home/matjaz/env/lib/python3.6/site-packages/selenium/webdriver/firefox/webdriver.py", line 152, in __init__
    keep_alive=True)
  File "/home/matjaz/env/lib/python3.6/site-packages/selenium/webdriver/remote/webdriver.py", line 98, in __init__
    self.start_session(desired_capabilities, browser_profile)
  File "/home/matjaz/env/lib/python3.6/site-packages/selenium/webdriver/remote/webdriver.py", line 185, in start_session
    response = self.execute(Command.NEW_SESSION, parameters)
  File "/home/matjaz/env/lib/python3.6/site-packages/selenium/webdriver/remote/webdriver.py", line 249, in execute
    self.error_handler.check_response(response)
  File "/home/matjaz/env/lib/python3.6/site-packages/selenium/webdriver/remote/errorhandler.py", line 194, in check_response
    raise exception_class(message, screen, stacktrace)
selenium.common.exceptions.WebDriverException: Message: Unable to find a matching set of capabilities

[AutomatedTester]

unforunately... no one in my team can reproduce this issue

[lmtierney]

@mfin with geckodriver 0.16 and firefox 53?

[thewinduppirate]

On Arch linux with:
python 3.6.1-1
firefox 53.0-1
geckodriver 0.16.0-1
python-selenium 3.4.0-1

@mfin's test produces the same result for me.

Traceback (most recent call last):
  File "./test.py", line 5, in <module>
    driver = webdriver.Firefox()
  File "/usr/lib/python3.6/site-packages/selenium/webdriver/firefox/webdriver.py", line 152, in __init__
    keep_alive=True)
  File "/usr/lib/python3.6/site-packages/selenium/webdriver/remote/webdriver.py", line 98, in __init__
    self.start_session(desired_capabilities, browser_profile)
  File "/usr/lib/python3.6/site-packages/selenium/webdriver/remote/webdriver.py", line 185, in start_session
    response = self.execute(Command.NEW_SESSION, parameters)
  File "/usr/lib/python3.6/site-packages/selenium/webdriver/remote/webdriver.py", line 249, in execute
    self.error_handler.check_response(response)
  File "/usr/lib/python3.6/site-packages/selenium/webdriver/remote/errorhandler.py", line 194, in check_response
    raise exception_class(message, screen, stacktrace)
selenium.common.exceptions.WebDriverException: Message: Unable to find a matching set of capabilities

[mfin]

@lmtierney yes. @thewinduppirate interesting, this looks to be Arch specific.

[mfin]

If I add the capabilities suggested by @jrbenny35, I get this:

Traceback (most recent call last):
  File "test.py", line 8, in <module>
    driver = webdriver.Firefox(capabilities=caps)
  File "/home/matjaz/Playground/test/env/lib/python3.6/site-packages/selenium/webdriver/firefox/webdriver.py", line 169, in __init__
    self.binary, timeout)
  File "/home/matjaz/Playground/test/env/lib/python3.6/site-packages/selenium/webdriver/firefox/extension_connection.py", line 52, in __init__
    self.binary.launch_browser(self.profile, timeout=timeout)
  File "/home/matjaz/Playground/test/env/lib/python3.6/site-packages/selenium/webdriver/firefox/firefox_binary.py", line 73, in launch_browser
    self._wait_until_connectable(timeout=timeout)
  File "/home/matjaz/Playground/test/env/lib/python3.6/site-packages/selenium/webdriver/firefox/firefox_binary.py", line 114, in _wait_until_connectable
    % (self.profile.path))
selenium.common.exceptions.WebDriverException: Message: Can't load the profile. Possible firefox version mismatch. You must use GeckoDriver instead for Firefox 48+. Profile Dir: /tmp/tmpvt157u03 If you specified a log_file in the FirefoxBinary constructor, check it for details.

[b4handjr]

@mfin That looks like an outdated firefox version error. That was my problem. I removed a line in my test and it was using FF47.

[moranl]

Same issue here, latest selenium, Firefox 53 (latest update today), geckodriver v0.16.0, MacOs (latest, updated)

[frenzymadness]

Hi. I have the same issue with geckodriver v0.16.0, Firefox 52.0.2, Python 3.5.3 and selenium 3.4.0 on Fedora 25.

[Kristinita]

Same problem as @jricardo27:

>>> window.run_command('run_selenium')
11:23:09 DEBUG selenium.webdriver.remote.remote_connection:478             _request() POST http://127.0.0.1:1646/session {"capabilities": {"firstMatch": [], "alwaysMatch": {"acceptInsecureCerts": true, "browserName": "firefox"}}, "desiredCapabilities": {"acceptInsecureCerts": true, "browserName": "firefox"}}
11:23:10 DEBUG selenium.webdriver.remote.remote_connection:565             _request() Finished Request
Traceback (most recent call last):
  File "D:\Sublime Text 3 x64\sublime_plugin.py", line 818, in run_
    return self.run(edit)
  File "D:\Sublime Text 3 x64\Data\Packages\TestPlugin\Selenium.py", line 26, in run
    run_tests(self.view)
  File "D:\Sublime Text 3 x64\Data\Packages\TestPlugin\Selenium.py", line 19, in run_tests
    browser = webdriver.Firefox()
  File "C:\Python36\Lib\site-packages\selenium\webdriver\firefox\webdriver.py", line 152, in __init__
    keep_alive=True)
  File "C:\Python36\Lib\site-packages\selenium\webdriver\remote\webdriver.py", line 98, in __init__
    self.start_session(desired_capabilities, browser_profile)
  File "C:\Python36\Lib\site-packages\selenium\webdriver\remote\webdriver.py", line 185, in start_session
    response = self.execute(Command.NEW_SESSION, parameters)
  File "C:\Python36\Lib\site-packages\selenium\webdriver\remote\webdriver.py", line 249, in execute
    self.error_handler.check_response(response)
  File "C:\Python36\Lib\site-packages\selenium\webdriver\remote\errorhandler.py", line 194, in check_response
    raise exception_class(message, screen, stacktrace)
selenium.common.exceptions.WebDriverException: Message: Unable to find a matching set of capabilities

Environment

Operating system and version:
Windows 10 Enterprise LTSB 64-bit EN
Python:
3.6.1
Selenium:
3.4.0
Firefox:
53.0 (64-bit)
geckodriver:
0.16.0

Thanks.

[jgraham]

For users experiencing this problem on Linux, can you tell me the following things:

• What's the firefox path i.e. the result of runing which firefox?
• What's the result of running file on the output of the above? i.e. file $(which firefox).
• Does the directory containing the firefox binary (after following any symlinks) contain an application.ini and platfom.ini file?
• What's the contents of the above files?

I suspect that a short term workaround for the bug may be to pass in an explicit path to the Firefox binary, after following any symlinks, in the capabilities i.e. something like {moz:firefoxOptions: {binary: /usr/lib/firefox/firefox}.

[mfin]

@jgraham firefox is in /bin, which is linked to /usr/bin, no *.ini files there also.

matjaz ~ $ which firefox
/bin/firefox
matjaz ~ $ file /bin/firefox
/bin/firefox: POSIX shell script, ASCII text executable
matjaz ~ $ ls -lah /bin
lrwxrwxrwx 1 root root 7 mar 26 23:57 /bin -> usr/bin
matjaz ~ $ ls /usr/bin/*.ini
/bin/ls: cannot access '/usr/bin/*.ini': No such file or directory

[thewinduppirate]

For me:

% which firefox
/usr/bin/firefox
% file$(which firefox)
/usr/bin/firefox: POSIX shell script, ASCII text executable

No *.ini files either.

[jgraham]

OK, so we didn't consider the possibility of the firefox executable being a shell script outside the firefox directory. As a short term workaround, if you look in that shell script you should be able to find the real binary path and use that as a capability when you launch geckodriver.

[thewinduppirate]

@jgraham Thanks for the info.

Firefox now launches correctly after amending the test

#!/usr/bin/env python3

from selenium import webdriver
from selenium.webdriver.firefox.firefox_binary import FirefoxBinary

binary = FirefoxBinary('/usr/lib/firefox/firefox')
driver = webdriver.Firefox(firefox_binary=binary)
driver.get('https://google.com')

[mfin]

@jgraham yes, I'm confirming that this solves the issue.

[jgraham]

Great! Thanks for the debugging information. I'll try to come up with a good solution for this and get a release of geckodriver out with it fixed.

[alimp5]

Hi,

I've same issue with Python Selenium.

[=] FireFox:
52.1.0 - 64 bit
[=] Selenium:
3.4.0
[=] Python:
2.7.13
[=] OS:
Linux - (Kali 64 bit) - dist upgraded to latest version

output:
/usr/bin/python /root/Desktop/ashiyane/ashiyane-alimp5.py
Traceback (most recent call last):
File "/root/Desktop/ashiyane/ashiyane-alimp5.py", line 12, in
driver = webdriver.Firefox(firefox_binary=binary)
File "/usr/local/lib/python2.7/dist-packages/selenium/webdriver/firefox/webdriver.py", line 152, in init
keep_alive=True)
File "/usr/local/lib/python2.7/dist-packages/selenium/webdriver/remote/webdriver.py", line 98, in init
self.start_session(desired_capabilities, browser_profile)
File "/usr/local/lib/python2.7/dist-packages/selenium/webdriver/remote/webdriver.py", line 185, in start_session
response = self.execute(Command.NEW_SESSION, parameters)
File "/usr/local/lib/python2.7/dist-packages/selenium/webdriver/remote/webdriver.py", line 249, in execute
self.error_handler.check_response(response)
File "/usr/local/lib/python2.7/dist-packages/selenium/webdriver/remote/errorhandler.py", line 194, in check_response
raise exception_class(message, screen, stacktrace)
selenium.common.exceptions.WebDriverException: Message: Unable to find a matching set of capabilities

Process finished with exit code 1

please fix this issue :(

Thanks

[alimp5]

I used technique below, and selenium is working now.

capabilities = webdriver.DesiredCapabilities().FIREFOX
capabilities["marionette"] = False
binary = FirefoxBinary(r'/usr/bin/firefox')
driver = webdriver.Firefox(firefox_binary=binary, capabilities=capabilities)

Reference (Idea):
http://seleniumsimplified.com/2017/03/changes-in-selenium-webdriver-3-1-0-3-2-0-3-3-0-and-3-3-1-for-java/

Thanks

[vickyeee861]

am using win 8, 64 bit os, i installed python 27,robot frame work latest version, selenium2library latest version, geckodriver 0.16.0, i have run the suite but it's didnt run, i got a same issue. which is " cannot capture screenshot because the browser is not open" could you please anyone help to me.

[vickyeee861]

oh yes... i had fixed that issue. thank you for good info.

[vguzev]

In my case this error was also caused by portable firefox.

Portable firefox has PortableFirefox.exe in the root folder and when you try to run it with Selenium it just opens Firefox's browser and then you get this "Unable to find matching capabilities" error.

In order to fix this you need to replace the path to PortableFirefox.exe with the path to firefox.exe that is located somewhere further down in the directory of portable firefox. In my case it was located in App/Firefox/.

I.e. as far as I understand PortableFirefox.exe is just a some kind of wrapper for firefox.exe and should not be used with Selenium. Have no idea why it is not mentioned in the docs.

[marxmit7]

for the mac users only
I also went through this problem and solved it through this link https://amit2rockon.github.io/codesync/blog/2018/02/02/webdrivers.html

[scharlack]

Mac user here. If it helps anyone I fixed this by making sure Firefox was named "Firefox" and in the Applications folder. I had the error when it was named "Firefox 58" (I have multiple versions).

[dataf3l]

It happened to me too, all I had to do was "apt install firefox"

[shek34575]

Actually the GeckoDriver has been introduced for selenium versions greater than 3.0.So in our progrem,
when we write
System.setProperty("webdriver.gecko.driver","path to the webdriver");
webDriver driver=new FireFoxDriver();
It will launch the Firefox instance.Now problem here is that Selenium 3.0 and above supports Firefox versions 50 and above only .So if we are using old versions of firefox like 45 ,47 etc then our firefox will not launch though our code is correct.

[arudmin]

same problem

selenium.common.exceptions.SessionNotCreatedException: Message: Unable to find a matching set of capabilities

geckodriver was installed via brew

geckodriver 0.20.1 is already installed and up-to-date

UPD. Solved!
Just install firefox:
brew install caskroom/cask /firefox

[fedpinx]

If you have Firefox 64-bits version, then download Gecko 64-bits version, same for 32-bits. This solved my problem.

[himanshub16]

For me, the cause of this problem was the incorrect binary path. I am using Firefox Developer Edition and the path of binary is /usr/bin/firefox-developer-edition on Arch Linux.
If someone steps on the same problem using Firefox Developer Edition, take care of the path.

[mexicarne]

Hello, I have the same issue with:

Python 3.7.0
Firefox 62.0
geckodriver-0.21.0
selenium 3.14.0 (from pypi)
FreeBSD 12

This code doesn't work:

from selenium import webdriver

driver = webdriver.Firefox()

Traceback (most recent call last):
  File "1.py", line 6, in <module>
    driver = webdriver.Firefox()
  File "/tmp/sel/lib/python3.7/site-packages/selenium/webdriver/firefox/webdriver.py", line 167, in __init__
    keep_alive=True)
  File "/tmp/sel/lib/python3.7/site-packages/selenium/webdriver/remote/webdriver.py", line 156, in __init__
    self.start_session(capabilities, browser_profile)
  File "/tmp/sel/lib/python3.7/site-packages/selenium/webdriver/remote/webdriver.py", line 251, in start_session
    response = self.execute(Command.NEW_SESSION, parameters)
  File "/tmp/sel/lib/python3.7/site-packages/selenium/webdriver/remote/webdriver.py", line 320, in execute
    self.error_handler.check_response(response)
  File "/tmp/sel/lib/python3.7/site-packages/selenium/webdriver/remote/errorhandler.py", line 242, in check_response
    raise exception_class(message, screen, stacktrace)
selenium.common.exceptions.SessionNotCreatedException: Message: Unable to find a matching set of capabilities

while this does:

from selenium import webdriver
from selenium.webdriver.firefox.firefox_binary import FirefoxBinary

binary = FirefoxBinary('/usr/local/bin/firefox')
driver = webdriver.Firefox(firefox_binary=binary)

> which firefox
/usr/local/bin/firefox
> ls -l /usr/local/bin/firefox
lrwxr-xr-x  1 root  wheel  30 Sep  4 03:26 /usr/local/bin/firefox -> /usr/local/lib/firefox/firefox

[daredevilbsd]

 python3.6 fuck.py
Traceback (most recent call last):
  File "fuck.py", line 5, in <module>
    driver = webdriver.Firefox(firefox_binary=binary)
  File "/usr/local/lib/python3.6/site-packages/selenium/webdriver/firefox/webdriver.py", line 162, in __init__
    keep_alive=True)
  File "/usr/local/lib/python3.6/site-packages/selenium/webdriver/remote/webdriver.py", line 154, in __init__
    self.start_session(desired_capabilities, browser_profile)
  File "/usr/local/lib/python3.6/site-packages/selenium/webdriver/remote/webdriver.py", line 243, in start_session
    response = self.execute(Command.NEW_SESSION, parameters)
  File "/usr/local/lib/python3.6/site-packages/selenium/webdriver/remote/webdriver.py", line 312, in execute
    self.error_handler.check_response(response)
  File "/usr/local/lib/python3.6/site-packages/selenium/webdriver/remote/errorhandler.py", line 242, in check_response
    raise exception_class(message, screen, stacktrace)
selenium.common.exceptions.WebDriverException: Message: Process unexpectedly closed with status 1

Same here I have spent now days on it. Should we again ditch BSD just because something does not work?!

[qwuscu]

Have same issue on windows as well, any suggestions? already gave FirefoxBinary

    binary = FirefoxBinary('C:\\Program Files (x86)\\Mozilla Firefox\\firefox.exe')
    driver = webdriver.Firefox(firefox_binary=binary)
    driver.maximize_window

[barancev]

@daredevilbsd Keep calm, the issue was closed by its author (see #3884 (comment)), not a selenium team member. The author decided that his issue was resolved. And his issue was not related to FreeBSD.

Hijacking a bug report that is not related to your problem and was closed by the author more than a year ago looks suboptimal.

[deltaoui]

Guys download the firefox binary from here https://ftp.mozilla.org/pub/firefox/releases/46.0.1/
Then use the following code by assigning the binary path to the one you just downloaded:

capabilities = webdriver.DesiredCapabilities().FIREFOX
capabilities["marionette"] = False
binary = FirefoxBinary(r'PATH_TO/firefox-sdk/bin/Firefox.app/Contents/MacOS/firefox') //use the path leading to the binary here
fp = webdriver.FirefoxProfile()
driver = webdriver.Firefox(firefox_binary=binary,  firefox_profile=fp,capabilities=capabilities)

[ben174]

I was able to solve this by simply installing Firefox. Just having the webdriver alone isn't enough, you must have the desktop app as well.

[UsamaIslam]

I have firefox 64bit installed and was using gekodriver32bit resolved the issue by simply downloading gekodriver64bit

[luisrock]

Ubuntu 16: "apt install firefox" did the trick.

[kelvinwop]

Install latest firefox and install latest geckodriver fixed it