WordPress software is constantly being improved, and your installation should be upgraded as often as possible.
There are pros and cons to upgrading your WordPress installation after launching a website; however, the benefits greatly outweigh the risks.
WordPress is open source software. Like all open source software, when an upgrade comes out, the details of that upgrade are made public. If one of them is a security fix, then someone with malicious intent could use that information to their advantage – potentially hacking into any WordPress website that has not been upgraded in the meantime. It’s best to upgrade your WordPress installation as soon as a security fix is released.
Using an older version of WordPress, you might be doing many things the long way!
There is always a risk that software will not work correctly after an upgrade. With WordPress and other open source software, the variety of third-party themes and plugins increases that risk. It is possible that after an upgrade, a particular theme or plugin will no longer work properly and/or cause errors on your website. iMarketing will investigate this for you and provide an improved solution.