WordPress plugin conflict: the halving method step by step, with an example
You find a WordPress plugin conflict with the halving method. Deactivate half of your plugins and check the symptom. If it's gone, the culprit is in the half you switched off; if not, it's in the half still running. Keep splitting until one is left. The safest way is troubleshooting mode, which disables plugins only for you, not for customers.
Author: The TellMyShop team. A guide for WordPress site and WooCommerce store owners: the cause, the manual fix and the same work in a chat conversation.
Last updated: · 6 min read
Plugin conflict: how to recognise it
A conflict is when two plugins work fine on their own but break something together. Or a plugin doesn't get along with your theme or PHP version. Typical symptoms: the “Add to cart” button does nothing, a category filter doesn't reload, the contact form won't send, blocks vanish in the editor, or one particular admin screen comes up blank.
First rule out two situations that have their own guides. If the whole site shows a critical error message, go to the post on the WordPress critical error. If the problem started right after you clicked Update, start with WordPress broken after an update. This post covers the harder case: something is wrong, nobody knows since when or why, and there are dozens of plugins.
Before you start switching off: two minutes with the clues
Sometimes halving isn't needed at all, because the guilty plugin signed its name in the log.
- The error log. A PHP message includes a file path, and the path contains the plugin's folder name. Where to find it and how to read it is in the post about WordPress error logs.
- Site health. Tools → Site Health shows an outdated PHP version and other problems that can cause conflict-like symptoms on their own.
- Recent changes. A new plugin, an overnight automatic update, a change in cache settings. The most recent change is the first suspect.
If the clues say nothing and the symptom is in the browser (a button, a slider, a pop-up), move on to halving.
The halving method on 23 plugins
A store has 23 active plugins. For a few days the variation picker on the product page hasn't worked: the customer clicks a size and the price doesn't change. Nothing in the logs. WooCommerce and two payment plugins stay active, so there are 20 suspects.
Switching them off one by one takes up to 20 rounds. Halving settles it in five.
| Round | Plugins deactivated | Result | Next step |
|---|---|---|---|
| 1 | 10 of the 20 suspects (group A) | variation picker works | culprit is in group A, reactivate group B |
| 2 | 5 of the 10 in group A | still broken | culprit is in the other 5 |
| 3 | 3 of those 5 | works | culprit is among these 3 |
| 4 | 2 of the 3 | still broken | culprit is the third plugin |
| 5 | only that one | works | confirmed |
Rules that save rounds:
- Write down the plugin list before you start. Name, whether it was active, version. After the test you go back to exactly that state.
- Leave WooCommerce and payments out of the suspects. The store doesn't work without them, so they stay active unless everything else fails.
- After each round, check the same symptom the same way. Same product, same size, a private window, cache cleared.
- Note the result of every round. By round three, memory starts mixing up the groups.
- Confirm at the end. Activate everything except the plugin you found and check once more.
If the problem disappears whichever half you switch off, two plugins from different groups are clashing. Keep one group active and add parts of the other back until the symptom returns.
Troubleshooting mode: disabling plugins just for you
Deactivating a plugin in the plugin list affects everyone. In a store, that means for several rounds customers may see the site without filters, without live chat or without the shipping calculator.
That's why the WordPress community recommends the Health Check & Troubleshooting plugin. Its troubleshooting mode disables plugins and switches to a default theme only in your session. You enable plugins one at a time and check the symptom, while customers see the normal store. The WordPress support handbook walks through it step by step, and the Learn WordPress lesson shows the whole method with examples. The Yoast knowledge base describes a similar procedure for reports about its own plugin.
The mode has one limit: it only works for the logged-in person. When the symptom shows only for customers, for example at guest checkout, you need a staging copy from your host or live deactivation outside busy hours.
What to do once you know which plugin
Finding the culprit is half the job. You have four options, from least to most disruptive:
- Update. Check whether the author has released a newer version with a fix.
- Report it to the author. Say which plugin or theme it clashes with, the versions, and how to reproduce the symptom. Your notes from the halving help a lot.
- Leave it deactivated. If the plugin isn't essential, keep it off until it's fixed.
- Replace it. If the author stays silent, look for another plugin that does the same job.
While you're at it, look at the list from round one. If you can't say what half the plugins do, read the post on unused WordPress plugins.
How the chat helps you find a conflict
The TellMyShop plugin for WordPress and WooCommerce starts with the clues. In TellMyShop Free, your chat (Claude or ChatGPT) reads the PHP, WordPress and WooCommerce error logs, site health and the plugin list with versions and updates. That's often enough to name a suspect without switching anything off.
When the logs are silent, the chat lays out a halving plan: it splits the plugins into groups, sets WooCommerce and payments aside and keeps notes on each round. You check the symptom in the browser, because the chat can't click the hoodie size for you.
You: On the product page, choosing a size doesn't change the price. Anything in the logs?
Your chat: There are no errors linked to the product page in the last 7 days of logs. You have 23 active plugins. I suggest halving. WooCommerce and the two payment plugins stay active. Round 1, I'll deactivate 10 plugins from group A:
Their settings stay. Deactivate them?
You: Yes.
Your chat: Deactivated. Check the size picker in a private window and tell me whether it works.
You: It works.
Your chat: The culprit is in group A. In the next preview I'll reactivate the group and deactivate 5 of them.
Card status: waiting for your “yes”old version: Example Slider, Example Reviews, Example Colour Swatches and 8 more: active
new version: the same 10 plugins: deactivated
The names and numbers in this conversation are examples. Deactivating and activating plugins works in TellMyShop Pro once you turn on the Plugins switch in the plugin panel, up to 10 plugins per step. The switch lasts 24 hours and needs a database backup from today. Each round has a preview and your approval, goes into the change history, and you can undo a deactivation with one request. For payment and shipping plugins, the chat warns you before the change.
Remember that the chat deactivates plugins on the live site, for everyone. Troubleshooting mode just for you comes from the Health Check plugin, not from TellMyShop. When the whole site is down with a critical error, the TellMyShop plugin won't respond either, because it runs inside WordPress.
You can download the free version from the TellMyShop Free page. Read more about the plugin on the TellMyShop for WordPress and WooCommerce page, and Pro prices are on the pricing page.
Questions and answers
How do I find which plugin is causing a problem in WordPress?
Deactivate half of your plugins and check whether the problem has gone. Then keep splitting whichever half holds the culprit until one plugin is left. With twenty-odd plugins that's a few rounds instead of switching each one off in turn.
Does deactivating a plugin delete its settings?
No. A deactivated plugin stays on the server along with its settings and data in the database. When you activate it again, it works as it did before. Only deleting the plugin can remove its data.
How can I look for a conflict without customers noticing?
Use the troubleshooting mode of the Health Check & Troubleshooting plugin. It disables plugins and switches the theme only for you, while visitors keep seeing the normal site. The other route is a staging copy of the site from your host.
What if the problem disappears whichever half I switch off?
That means two plugins clash and each ended up in a different half. Keep one half active and add the other half back piece by piece until the problem returns. Then you have the pair that doesn't get along.
Can the chat find a plugin conflict on its own?
The chat reads error logs, site health and the plugin list, which is often enough to point to a suspect. When the error leaves no trace in the logs, it guides the halving, and in TellMyShop Pro with the Plugins switch on it deactivates and activates groups of plugins. You check the symptom in the browser yourself.
WordPress is a trademark of the WordPress Foundation. WooCommerce is a trademark of Automattic Inc. Claude is a trademark of Anthropic PBC. ChatGPT and OpenAI are trademarks of OpenAI. TellMyShop is not affiliated with these companies.