Chromedriver --screenshot not working in headless mode?

selenium selenium-webdriver webdriver selenium-chromedriver headless

The window-size argument expects string format 800,600, try this instead:

chromeOptions.addArguments("window-size=1980,960");

Also, you have a typo in your screenshot argument:

chromeOptions.addArguments("screenshot");

Here's a great reference of all available Chromium command line switches:

CodeHunter