Starting with what WordPress have said.
Woocommerce posted an announcement about the impending 3.0 update on their development blog on 13th March. It says; “We’re re-versioning WooCommerce 2.7 as WooCommerce 3.0.0, and releasing this on 4th April 2017. We found a critical bug in the way the system handles timestamps, which wasn’t caught sooner, and have had numerous requests from third-party extension developers for more testing time, due to the scale of changes in this release.”
That sounds a little ominous. Then I spotted a comment about Avada, one of the most popular themes on the market. I visited the Theme Fusion website and found this warning; “The New WooCommerce 2.7 Is Only Compatible With Avada 5.1.” Just below that was written; “WooCommerce has held back their 2.7 release and are making it into 3.0 to be released on April 4th.” Avada 5.1+ is still compatible with the current live version of WooCommerce.”
Summarising that and translating it into usable English, it means that all versions of Avada prior to the current 5.1 versions will be incompatible with WooCommerce 2.7 (or WooCommerce 3.0 as it will be called). So, if you don’t have a 5.1 version of Avada and you update to Woocommerce 3.0, your shop’s going to malfunction. That’s an ‘Oops’ then.
Don’t get me wrong; it’s not just Avada. This is something that will probably affect countless themes with Woocommerce compatability built in, and of course WooCommerce extensions and plugins. The effects may vary from theme to theme, and some WooCommerce extensions won’t be affected at all, whereas others will need to be updated. Some themes will be updated and available before WooCommerce releases 3.0 but many won’t. You can bet on that. Most premium plugins will have been updated before the release date too.
How should I deal with updating to WooCommerce 3.0?
First things first, disable auto-updating. Check the theme and any WooCommerce plugins you’re using and see if they all have updates available. Once updates are available, update them together. Then read the blogs relating to WooCommerce and your theme, maybe check the Facebook groups, and see what issues other users have had. Once it is clear that updates are going ahead without throwing up unexpected problems, go ahead and update your own site. AFTER taking a full restorable backup, of course.
What’s it all about anyway?
It seems to be a major update with a few twists thrown in for good measure. The detail doesn’t really matter to anybody other than developers, but it appears the potential problems are caused by the discovery of a critical bug in how WooCommerce handles timestamps. Since 2.7 was released in beta form there have been additional changes made to what will become WooCommerce 3.0 so beware of a plugin or theme that states it is 2.7 compatible. It needs to be compatible with 3.0. And you need a trustworthy backup plugin. Just in case.