I was getting this error in Laravel as I created a new app using the latest version (that is
6.2). Not sure why, the class would work locally but not remotely (on a deployment running in Ubuntu 18.04.3 on DigitalOcean to be precise).
I was using
\ResourceBundle::getLocales('') to get a list of valid locales present on a website and then using
in_array($needle, $array) to check whether a given locale is valid in PHP.
Here's how I fixed it.
composer require symfony/intlto install Symfony's Intl component.