You might come across this error when building a web application on maven using the command
This would be caused if maven is not aware of where the web.xml file is located.
If you follow the standard maven directory structure as
src/main/java src/main/resources src/main/webapp
You would have to copy the contents of WebContent [WEB-INF AND META-INF] to src/main/webapp folder – there maven would get it as expected.