Yesterday, WooCommerce 3.0 was released (read all the official dev notes here). We’d recommend NOT updating yet, particularly if you are not comfortable with creating staging environments. (WooCommerce is a really nice and simple shopping cart/eCommerce system designed as a plugin for WordPress).
If you did upgrade, we’re pretty sure something in your site is now broken.If it is, Immediately “downgrade” your WooCommerce by removing the plugin entirely and download and upload the older (2.6) version.
If you didn’t, wait a little longer. Your theme and plugin developers need to see if everything is compatible with WooCommerce 3.0 first… and very likely they will release an update in the next few days. Or at least, TEST the new Woo 3.0 on a staging install, so that your live site is not affected by this huge change.
Also, they completely remodeled the product gallery, improved the performance/speed, and released other edits – you can find out more via the official link above.
It’s almost guaranteed you’ll see a WooCommerce 3.0.1 very soon (note that last “.1”), to fix the first reported bugs. So, follow our suggestion and WAIT until 3.0.1 or 3.0.2 (perhaps even a month or so), so that at least the major bugs will have been addressed by then.
This begs the question: when should I perform a major version upgrade of ANY plugin? It’s a difficult question to answer, as there are various levels of complexity with any plugin. WooCommerce is pretty complex. Our recommendation would be to always perform minor upgrades; they often address security issues or minor improvements. Major updates can be more complex, introducing completely new database structures. More importantly, they can often break other plugins which are dependent on this ‘parent’ plugin. If in doubt, please call or email us for advice.