Plugin conflicts

A plugin conflict is far more likely than a theme regression. This page is the procedure for finding and confirming one.

The bisect procedure

This works on every problem and takes five minutes.

Back up first

Files and database. This is what makes the next steps safe.

Deactivate every plugin

Plugins → Installed Plugins → Deactivate using the bulk action at the top.

Check the site

If the problem is gone, a plugin is the cause and you have narrowed it to that set.

Reactivate the first half

Check again.

Reactivate the second half

Check again.

Repeat within the failing half

Until you have isolated one plugin.

Confirm the culprit

Deactivate just that plugin and verify the problem returns when it is active. This final confirmation matters — it rules out coincidence.

Deactivating plugins can break the site in new ways. A page builder, a forms plugin, or a security plugin may be required for other things to work. Have your backup ready, and do this on staging if you have it.

Faster methods

Via WP-CLI

Much faster than clicking when you have shell access.

# Deactivate everything
wp plugin deactivate --all

# List what's currently inactive
wp plugin list --status=inactive

# Reactivate one
wp plugin activate elementor

Via the database

If the dashboard is unreachable, deactivate by editing the active_plugins option.

UPDATE wp_options
SET option_value = 'a:0:{}'
WHERE option_name = 'active_plugins';

Back up the database before running that query. It deactivates every plugin, including your security plugins. Do it only when you have no other way in, and do not do it on a production site without a tested restore path.

Confirming it is really a conflict

The problem appeared right after a plugin update

Strong signal. Check each plugin’s update timestamp against when the problem started.

The problem followed a plugin install

Strong signal, though some plugins conflict with each other rather than with the theme.

The problem follows your theme switch

Also plausible — a plugin may have been built for your previous theme’s architecture.

The problem appears only with caching

A “conflict” that only exists when a stale cached file is served. Clear all caches first.

Where conflicts show up

Symptom	Usual cause
Mobile menu will not open	JavaScript error from a builder, slider, chat widget, or cookie banner
Header missing on some pages	A page builder or header plugin that removes the theme header
Layout broken after a plugin install	CSS specificity conflict, usually aggressive
Colors overridden	A plugin injecting its own global styles
Content width wrong	A plugin setting a container width, or a builder’s full-width mode
Dark mode not applying	A cache serving stale CSS, or a plugin forcing a colour scheme
Customizer will not save	A security plugin blocking the request
Everything looks unstyled	A CSS optimiser double-processing the theme’s stylesheet

The CSS optimiser problem

This one is specific to this theme and worth understanding.

The theme’s main stylesheet is already served without blocking render — it uses a media="print" onload="this.media='all'" swap with a <noscript> fallback.A CSS optimisation plugin that also defers, inlines, or reorders stylesheets may double-process it and produce an unstyled or broken site. Fonts are preloaded in the same way.If you install a caching plugin with CSS optimisation and the site goes unstyled, disable that specific feature first.

See Performance.

Plugins most likely to conflict

Category	Why
Other page builders	More than one active at once is asking for trouble
Other themes’ companion plugins	Built for a different theme’s architecture
Aggressive CSS optimisers	Double-process the theme’s load strategy
Header/footer builder plugins	Expect to own the header, which the theme does not offer
Chat and popup widgets	Frequently inject JavaScript that throws on load
Login customisation plugins	Inject markup that changes body classes the theme relies on
Maintenance mode plugins	Replace the whole front end

If the conflict is with the theme

Sometimes the finding is that the plugin is genuinely incompatible with this theme rather than buggy.

A header or footer builder plugin

This theme’s header and footer are PHP. It does not register any page builder theme locations, so a header builder plugin has nothing to attach to. Use a child theme instead — see Child themes.

A plugin expecting a theme options page

Some plugins read a theme’s registered settings. This theme keeps everything in the Customizer, which such plugins cannot read.

A theme switcher or styling plugin

Plugins designed to restyle other themes may inject CSS that fights this theme’s tokens.

If it is a plugin bug

Report it to the plugin author first

A plugin that conflicts with a third-party theme is usually a plugin bug, or a plugin that should detect and adapt.

Then note the theme interaction

Tell the plugin author exactly which theme and version, and what breaks. Specific reports get fixed.

Roll back the plugin version

Most plugins let you install a previous version from the plugin page. It is a temporary fix that buys time.

After you fix it

Clear all caches

The cached CSS and JavaScript from the conflicted state will persist otherwise.

Clear the object cache

Restarting PHP often helps. Some hosts flush on request.

Re-test the same page

Confirm the fix in the same place you found the problem.

Test on mobile

Many conflicts only manifest at certain breakpoints.

Audit your plugin list

If you found one conflict, there may be more. Consider removing plugins you have not used in months.

Prevention

Action	Prevents
Update plugins one at a time	Multiple simultaneous unknowns
Test updates on staging	Production outages
Remove unused plugins	Most conflicts, and a performance win
Keep a tested backup	Everything
Clear cache after updates	Stale-asset “conflicts” that are not conflicts

Plugin compatibility

What to expect from specific plugins.

Blank site or fatal error

When a conflict is severe enough to take the site down.

Introduction

Getting started

Customization

Plugin conflicts

Plugin conflicts

The bisect procedure

Faster methods

Via WP-CLI

Via the database

Confirming it is really a conflict

Where conflicts show up

The CSS optimiser problem

Plugins most likely to conflict

If the conflict is with the theme

If it is a plugin bug

After you fix it

Prevention

Plugin compatibility

Blank site or fatal error

​Plugin conflicts

​The bisect procedure

​Faster methods

​Via WP-CLI

​Via the database

​Confirming it is really a conflict

​Where conflicts show up

​The CSS optimiser problem

​Plugins most likely to conflict

​If the conflict is with the theme

​If it is a plugin bug

​After you fix it

​Prevention

​Related

Plugin compatibility

Blank site or fatal error

Plugin conflicts

The bisect procedure

Faster methods

Via WP-CLI

Via the database

Confirming it is really a conflict

Where conflicts show up

The CSS optimiser problem

Plugins most likely to conflict

If the conflict is with the theme

If it is a plugin bug

After you fix it

Prevention

Related