Puppet 4 has been released and breaks compatibility with version 3. Therefore users will need to upgrade a server to Puppet 4 before updating their clients. Note that if only a Puppet 4 server is available, Puppet 3 clients will not work. Also a number of locations for things have changed including the config, manifest and module files. You will need to follow upgrade instructions for your servers and clients:

* [https://docs.puppetlabs.com/puppet/4.0/reference/upgrade_server.html%5D%5B1]

* [https://docs.puppetlabs.com/puppet/4.0/reference/upgrade_agent.html%5D%5B2]

[1]: https://docs.puppetlabs.com/puppet/4.0/reference/upgrade_server.html

[2]: https://docs.puppetlabs.com/puppet/4.0/reference/upgrade_agent.html

URL: https://www.archlinux.org/news/puppet-40-enters-community/