I faced the same problem today. You need to enable the intl PHP extension in your PHP configuration (.ini).
Solution Xampp (Windows)
- Open
/xampp/php/php.ini
- Change
;extension=php_intl.dll to extension=php_intl.dll (remove the semicolon)
- Copy all the
/xamp/php/ic*.dll files to /xampp/apache/bin
- Restart apache in the Xampp control panel
Solution Linux (thanks to Annamalai Somasundaram)
Install the php5-intl extension sudo apt-get install php5-intl
1.1. Alternatively use sudo yum install php5-intl if you are on CentOS or Fedora.
Restart apache sudo service apache2 restart
Solution Mac/OSX (homebrew) (thanks to deizel)
- Install the php5-intl extension
brew install php56-intl
- If you get
No available formula for php56-intl follow these instructions.
- Restart apache
sudo apachectl restart
Eventually you can run composer install to check if it's working.