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WooCommerce checkout stopped working? How to find out which plugin did it.

By Phillip Clapham · October 18, 2026

If checkout broke, treat it like it’s costing you money, because it is. First question: what changed? A plugin or theme update, a WordPress update, or your host moving PHP forward. That last one is the one people miss. It’s covered in this post.

WooCommerce documents the way to find the culprit: a conflict test (How to test for plugin and theme conflicts). It’s boring and it works.

The test

  1. Back up first. WooCommerce highly recommends it. Turning plugins off and on usually doesn’t cause trouble, per that page, but usually is doing a lot of work on a live store.
  2. Update everything. A newer version may already have fixed the clash.
  3. Switch to a default theme, like Storefront. If the problem goes away, it’s your theme.
  4. Turn off every plugin except WooCommerce and the extension where you see the problem. Then do the exact thing that broke.
  5. Fixed? Turn plugins back on one at a time, testing after each. The one that brings the problem back is your answer.

Two catches. Some things aren’t plugins: drop-ins and must-use plugins, which your host may have to turn off for you. And browser caching can make a fixed checkout look broken, so test with caching off.

The part that bites

Doing this on a live store means your customers are watching you do it. WooCommerce’s own advice is to test on a staging copy, a clone of your site, so you can break things without losing orders. If you don’t have one, that page points to a couple of tools for making one.

When to call someone

  • Checkout is down and orders are walking away.
  • You turned plugins off on the live store and now it’s worse.
  • You found the plugin, but it’s one you can’t run the store without. That needs a fix, not a removal.
  • You can’t tell which extension it is.

That’s a rescue. Send me the site and I’ll tell you what broke and what fixing it takes. How I run these is on the rescue page.

Stopping a repeat

Test updates on a copy before they go live, and have someone watching checkout afterward. And count your plugins. Every one is something that can break the checkout.