Running appium 1.8.1 in Linux against a device with Chrome 66.0.3359 this happens when trying to find an element on a webview after switching to web context (facebook login in a native app):
An unknown server-side error occurred while processing the command. Original error: No Chromedriver found that can automate Chrome ‘0.0.0’. See https://github.com/appium/appium/blob/master/docs/en/writing-running-appium/web/chromedriver.md for more details. (WARNING: The server did not provide any stacktrace information)
Same code running in 1.8.0 works fine.