This error appears mostly when Maven could not find the web.xml file. If you are following the default maven structure, make sure the webapp folder is named correctly – like not webapps or something like that.
Once you make sure, you can try by explicitly telling maven where the web.xml file is using
This error is quite explanatory in JSF.
I got once in a while when I work with dynamic generation of the components.
If you have this, the most common cause of this error would be you are trying to attach the an html component from your bean again.
Especially, if you have session scoped managed bean and you are attaching dynamically elements, may be one of your methods has already attached the component to the view (like the grid you are using for your component) and the other method is trying to attach it again.
If that is the case you might need to check the existence of the component in the grid (or any component you are using) before attaching it.
Also: see how to add session bean to request
One plus side of the compiled languages would be telling us every error during/after compilation which would save a lot time from chicanery. But, in JSF you may get unexpected error which is a silent.
The page would run and the action linked to, say command button or command link, may not be triggered.
If you got that, just check your form fields – especially if you are working with datatable, make sure all the conversion and validations are working as expected. If the validation/conversion is not working properly, then the framework would exit before reaching the backend.
One way to troubleshoot this would be to have <h:messages /> with appropriate attributes, like adding showDetail=”false” showSummary=”true”, on your form – that, definitely, would help you to debug the problem.