Selenium is giving " KeyError: 'sessionId' "

Upgrading from Selenium 3.2.0 to 3.7.0 fixed this error for me. I have geckodriver 0.19.1

pip install -U selenium

I did not go in detail with this, sorry for that, but perhaps this might help you or give you a useful hint:

The following worked for me under Ubuntu 16.04:

If you run the pip installer as a normal user account, it seems to create these two directories with contents:

• ~/.local/lib
• ~/.local/selenium

Somehow it can't update this correctly, so these two directories seemed to contain an old version of selenium and needed libs in my setup. I have deleted both of these subtrees, so importing the webdriver is now using the system wide installation of selenium, which I upgraded as root via

sudo pip install -U selenium

It then worked for me. Please also have a look which python version your script is using, I needed to tell bash that I am using python2.7 via the shebang at the start of the python script:

#!/usr/bin/python2.7# -*- coding: utf-8 -*-

Perhaps this got to do with which python bindings you have installed, but I don't know, this is only a guess, as I told above, I did not go very deeply into it, but it might give you a hint.

I hope it helps. Cheers!

I've resolved the issue by downgrading a selenium server version to v.2.x.

I.e. - instead of latest 3.x server version (selenium-server-standalone-3.141.59.jar) i have tried latest 2.x. selenium server version (selenium-server-standalone-2.53.1.jar)

My Python version:

Python 2.7.10robotframework==2.9.2robotframework-requests==0.4.5requests==2.11.1requests-oauthlib==0.7.0requests-toolbelt==0.7.0robotframework-selenium2library==1.8.0selenium==3.0.1requests-oauthlib==0.7.0requests-toolbelt==0.7.0

Other software:

ChromeDriver 77.0.3865.40Google Chrome Version 77.0.3865.90 (Official Build) (64-bit)Windows 10`