I installed protractor following this tutorial and when i use webdriver-manager update it says:
selenium standalone is up to date. chromedriver is up to date. >
For me the npm install and npm run update-webdriver commands just kept downloading the corrupt Chromedriver_x.xx.zip file. So I tried running webdriver-manager update, and it worked.
npm install
npm run update-webdriver
Chromedriver_x.xx.zip
webdriver-manager update