How do I fix 'Unprocessed view path found' error with ExceptionNotifier plugin in rails 2.1? | After upgrading a rails 1.2 website to 2.1, the [ExceptionNotifier plugin](http://agilewebdevelopment.com/plugins/exception_notifier) no longer works, complaining about this error:



> 
> ActionView::TemplateFinder::InvalidViewPath: Unprocessed view path
>  found:
>  "/path/to/appname/vendor/plugins/exception\_notification/lib/../views".
>  Set your view paths with #append\_view\_path, #prepend\_view\_path, or #view\_paths=.
> 
> 
> 


What causes it and how do I fix it?