WordPress plugin conflicts

A plugin conflict can occur when two or more WordPress tools attempt to modify the same functionality in incompatible ways.

Most conflicts can be resolved by identifying the overlapping feature and allowing only one tool to perform each task.

Symptoms

You are here because one of the following issues probably occurred:

• Website functionality suddenly stopped working.
• Published changes did not appear.
• CSS or JavaScript files failed to load.
• Layouts or styling appeared broken.
• JavaScript errors appeared in the browser console.
• Images are missing or were not processed correctly.
• Cache behavior became inconsistent.
• Plugin settings could not be saved.
• The WordPress admin area displayed unexpected errors.
• Forms, navigation, search, popups, or checkout functions stopped working.
• Performance became noticeably worse after enabling or updating a plugin.

A conflict does not always generate a PHP error. Multiple tools may modify the same requests or assets without producing an explicit error message.

Likely causes

Plugin conflicts involving EDGE are commonly caused by:

• More than one page-caching system
• Duplicate CSS or JavaScript optimization
• Multiple image optimization or lazy-loading tools
• Security rules blocking legitimate API, AJAX, or background requests
• Multiple CDN services or asset URL-rewriting features
• Different tools applying conflicting cache exclusions or purge behavior
• A recent plugin, theme, WordPress, or PHP update

Resolve the conflict

1. Record the problem

Before changing your configuration, record:

• The affected page, URL, or feature
• The approximate time the issue started
• The steps required to reproduce it
• Any recent WordPress, plugin, theme, or PHP updates
• The active plugin and theme versions
• Any browser-console errors
• Relevant plugin, PHP, or server log entries

This creates a baseline and helps you determine whether each change improves the issue.

2. Reproduce the issue

Confirm that the problem occurs consistently.

Test the affected page:

• In a private browser window
• While logged out of WordPress
• On more than one browser or device
• After clearing the browser cache
• Using the same steps each time

Consistent testing makes it easier to identify which change resolves the conflict.

3. Review logs and browser errors

Logs and browser tools can help identify the affected plugin, request, or asset.

Review the browser console

1. Open your browser’s Developer Tools.
2. Select Console.
3. Reload the affected page.
4. Look for JavaScript errors, blocked requests, or failed assets.

In most Windows browsers, you can open Developer Tools by pressing F12.

Also review the Network tab for files or requests returning errors such as 403, 404, or 500.

Review Performance Plugin logs

If the issue involves the Pressidium Performance Plugin, review the plugin’s Logs screen.

Look for:

• Connection or authentication errors
• Settings that could not be applied
• Image-processing failures
• Requests blocked by another plugin
• Communication failures between WordPress and EDGE

Review origin and PHP logs

If the issue appears to originate from WordPress or PHP, review the PHP and web server error logs provided by your hosting provider.

Record the relevant timestamp and error message before changing the configuration.

Review access logs

Use the Access Logs page in the Pressidium Dashboard to review recent HTTP requests.

Look for:

• Failed request status codes
• Requests that do not reach the expected URL
• Blocked API or asset requests
• Repeated requests to the affected page or resource

4. Isolate the conflicting plugin or feature

Do not assume that the entire plugin is incompatible. The conflict may involve only one feature, such as page caching, JavaScript deferring, image conversion, or rate limiting.

Start with the most recent change:

1. Disable the plugin or feature that was most recently installed, activated, updated, or configured.
2. Clear the relevant caches.
3. Test the affected functionality.
4. If the issue remains, restore the previous setting and test the next suspected feature.

To test whether a specific plugin conflicts directly with EDGE, disable that plugin, test the website, and then re-enable it before testing another plugin.

To identify a conflict between multiple third-party plugins:

1. Perform the test on staging.
2. Disable all non-essential plugins.
3. Confirm whether the issue disappears.
4. Re-enable the plugins one at a time.
5. Test after each plugin is enabled.
6. Stop when the issue returns.

Avoid disabling all plugins on a production website unless you are working during a controlled maintenance window.

5. Clear all relevant caches

Cached files or responses may cause the original symptom to remain after you change a setting.

Clear caches in the following order:

1. Clear any generated files or cache maintained by the affected plugin.
2. Clear the WordPress or origin cache, if present.
3. Purge the relevant EDGE cache.
4. Clear your browser cache or open a private browser window.
5. Test the original symptom again.

Repeat this process after each configuration change.

6. Choose one tool for each task

Avoid allowing multiple tools to perform the same operation.

For each overlapping feature, choose one of the following configurations.

Use the Pressidium feature

Choose this option when EDGE or the Pressidium Performance Plugin already provides the functionality you need.

This can:

• Reduce duplicate processing
• Simplify configuration
• Make troubleshooting easier
• Reduce conflicting rules or purge behavior

Use the third-party feature

Choose this option when a third-party plugin provides functionality that your website requires.

Disable only the equivalent EDGE or Performance Plugin feature. Keep unrelated Pressidium features enabled.

Use both for different tasks

Some plugins can operate alongside Pressidium tools when each system performs a different task.

For example, you may use one tool for image optimization and another for CSS optimization.

When using multiple tools:

• Do not enable the same feature in both.
• Change one setting at a time.
• Clear all relevant caches after each change.
• Test before applying the configuration to production.

Prefer the simplest configuration that meets your website’s requirements.

Features to review

Page caching

Page-caching plugins can create an additional caching layer alongside Pressidium EDGE.

Examples include:

• WP Rocket
• WP Super Cache
• W3 Total Cache
• LiteSpeed Cache
• Cache Enabler
• Breeze
• SG Optimizer

Installing one of these plugins does not automatically create a conflict.

Problems are more likely when multiple systems:

• Cache the same pages
• Use different cache exclusions
• Apply different cache lifetimes
• Purge content independently
• Preload or regenerate the same cache
• Handle cookies or logged-in users differently

Pressidium EDGE already provides managed edge caching designed for WordPress.

If another caching plugin is installed:

1. Review which caching features are enabled.
2. Disable overlapping page-caching features where appropriate.
3. Clear the plugin’s cache.
4. Purge the relevant EDGE cache.
5. Test the affected pages in a private browser window.

You may continue using unrelated plugin features that do not overlap with EDGE caching.

CSS and JavaScript optimization

Optimization plugins may modify CSS and JavaScript before the files are delivered to visitors.

Examples include:

• Autoptimize
• WP Rocket
• W3 Total Cache
• Fast Velocity Minify
• Hummingbird
• Asset CleanUp
• Perfmatters
• LiteSpeed Cache

These plugins may provide:

• CSS minification
• JavaScript minification
• File concatenation
• Script deferring or delaying
• Critical CSS generation
• Removal of unused CSS

Running multiple optimization systems against the same assets can cause:

• Broken layouts
• Missing styles
• JavaScript errors
• Features that stop working
• Assets loading in the wrong order

Use one tool for each CSS or JavaScript optimization task.

If you use the Pressidium Performance Plugin:

1. Open the Performance Plugin settings.
2. Review the active CSS and JavaScript optimization options.
3. Disable equivalent features in other plugins.
4. Clear all relevant caches.
5. Test important pages and interactive features.

Test at least:

• Navigation menus
• Forms
• Sliders and carousels
• Popups
• Search
• Account pages
• WooCommerce product, cart, and checkout pages
• Custom JavaScript functionality

If one file causes the problem, use a targeted exclusion instead of disabling optimization across the entire website.

Image optimization

Image optimization plugins commonly provide:

• Lossy or lossless compression
• Image resizing
• WebP generation
• AVIF generation
• Responsive image handling
• Lazy loading

Examples include:

• Smush
• ShortPixel
• Imagify
• EWWW Image Optimizer
• Optimole
• TinyPNG
• WebP Express
• Converter for Media

The Pressidium Performance Plugin includes image optimization for new and existing Media Library images, including WebP and AVIF conversion.

Using multiple image optimization tools against the same Media Library may:

• Recompress images that are already optimized
• Generate duplicate WebP or AVIF files
• Overwrite output produced by another tool
• Produce inconsistent image quality
• Complicate restoration and troubleshooting

Use a single image optimization workflow whenever possible.

Before changing tools:

1. Preserve the original images.
2. Disable automatic processing in the tool you are replacing.
3. Test a representative group of images.
4. Verify that thumbnails and full-size images load correctly.
5. Check desktop and mobile layouts.
6. Process the remaining Media Library only after the test succeeds.

Also confirm that only one tool provides lazy loading for the same images or iframes.

Security

Pressidium EDGE and WordPress security plugins operate at different layers.

EDGE filters requests before they reach your origin. WordPress security plugins operate after the requests reach the WordPress application.

Examples of WordPress security plugins include:

• Wordfence
• Solid Security
• Sucuri Security
• All-In-One Security
• Defender Security
• Shield Security
• MalCare

Using a WordPress security plugin alongside EDGE does not automatically create a conflict.

Conflicts are more likely when the plugin:

• Blocks communication with the Pressidium Performance Plugin
• Restricts REST API or AJAX requests
• Blocks scheduled background tasks
• Applies rate limits to legitimate requests
• Modifies proxy or visitor IP detection
• Prevents plugin settings from being saved
• Blocks image or asset processing

After installing, updating, or reconfiguring a security plugin:

1. Confirm that the Performance Plugin remains connected to EDGE.
2. Confirm that its settings can be saved.
3. Test WordPress login and password reset.
4. Test REST API and AJAX requests.
5. Test forms and WooCommerce checkout.
6. Confirm that scheduled tasks continue to run.
7. Verify that the security plugin records the correct visitor IP address.
8. Review firewall and blocking events if a legitimate request fails.

If a security rule blocks valid traffic, disable only the suspected rule or feature and test again.

Avoid disabling the entire security configuration unless necessary for a controlled test.

CDN and asset delivery

Some plugins and external services provide CDN functionality or rewrite asset URLs.

Examples include:

• Jetpack Site Accelerator
• CDN Enabler
• Bunny.net integrations
• WP Offload Media
• Cloudflare WordPress integrations
• LiteSpeed Cache CDN features
• W3 Total Cache CDN features

These services may:

• Rewrite CSS, JavaScript, image, or font URLs
• Proxy requests through another delivery network
• Modify cache-control headers
• Add another cache or proxy layer

Pressidium EDGE already provides global delivery for static and dynamic WordPress content.

If another tool also manages delivery:

1. Review which CDN or URL-rewriting features are active.
2. Disable duplicate delivery features where appropriate.
3. Confirm that asset URLs resolve correctly.
4. Clear all caches.
5. Test CSS, JavaScript, images, fonts, and downloads.

Some plugins also synchronize media to object storage. You may continue using that functionality when it does not duplicate EDGE delivery or interfere with cache behavior.

Common plugin scenarios

The following plugins are not categorically compatible or incompatible with EDGE. Review the features that are active in your configuration.

Plugin	Features to review	What to verify
WP Rocket	Page caching, cache preloading, CSS and JavaScript optimization, lazy loading, CDN rewriting	Use one system for each caching or optimization task, disable duplicate CDN rewriting, and test interactive pages
Autoptimize	CSS and JavaScript minification, concatenation, deferring, generated asset cache	Disable options that duplicate Performance Plugin features, clear generated files, and add targeted exclusions where necessary
Wordfence	Firewall rules, rate limiting, visitor IP detection, REST API access, AJAX, scheduled tasks	Confirm legitimate requests are not blocked, EDGE communication works, and visitor IP addresses are detected correctly

WP Rocket

WP Rocket can provide several features that overlap with EDGE or the Pressidium Performance Plugin.

To review the configuration:

1. Record which WP Rocket features are active.
2. Clear the WP Rocket cache.
3. Avoid using WP Rocket as an additional page-caching layer when EDGE is configured as the primary page cache.
4. Choose one tool for each CSS and JavaScript optimization task.
5. Disable CDN URL rewriting if EDGE will remain the primary delivery layer.
6. Clear all active caches.
7. Test important pages and interactive features.

You may keep unrelated WP Rocket features after testing them.

Autoptimize

Autoptimize may minify, combine, defer, or cache CSS and JavaScript files.

To review the configuration:

1. Identify the active CSS and JavaScript options.
2. Disable any option that duplicates an active Performance Plugin feature.
3. Clear the Autoptimize cache.
4. Clear all other active cache layers.
5. Test important pages and interactive elements.
6. Add targeted exclusions if a specific file causes the issue.

Use only one tool for each minification or concatenation task.

Wordfence

Wordfence may provide firewall rules, login protection, malware scanning, blocking, and rate limiting inside WordPress.

To review the configuration, confirm that:

• The Performance Plugin can save its settings.
• The Performance Plugin can communicate with EDGE.
• Wordfence records the correct visitor IP address.
• Login and password-reset requests work.
• REST API and AJAX requests work.
• Scheduled tasks continue to run.
• Rate-limiting rules do not block legitimate requests.
• Security rules do not interrupt image or asset processing.

If an action is blocked, review the corresponding Wordfence event and temporarily disable only the suspected rule or feature.

Verification

After changing the configuration:

1. Clear every active cache layer.
2. Reproduce the original test.
3. Confirm that the affected page or feature works consistently.
4. Check desktop and mobile layouts.
5. Test logged-in and logged-out behavior.
6. Test forms, menus, search, popups, and other interactive elements.
7. For WooCommerce sites, test products, cart, checkout, account pages, and payment redirects.
8. Review the browser console for new errors.
9. Confirm that CSS, JavaScript, images, fonts, and downloads load successfully.
10. Monitor request and performance behavior in the Pressidium Dashboard.

Do not consider the issue resolved until the original functionality works consistently under the same conditions that previously caused the problem.

Prevent future conflicts

Review features before installing a plugin

Before installing or updating a plugin:

1. Check whether it duplicates an EDGE or Performance Plugin feature.
2. Review the plugin vendor’s configuration and compatibility guidance.
3. Create a recent backup.
4. Test the change on staging.
5. Record the current working configuration.
6. Install or update one plugin at a time.
7. Test the website before making another change.

Pressidium does not publish a comprehensive certification list for third-party plugins or themes.

Compatibility may also change between plugin versions, so test important functionality after major updates.

Avoid duplicate functionality

Pay particular attention to:

• Page caching
• Cache preloading
• CSS minification
• JavaScript minification
• File concatenation
• Script deferring or delaying
• Critical CSS
• Removal of unused CSS
• Lazy loading
• Image compression
• WebP and AVIF generation
• CDN delivery
• Asset URL rewriting
• Firewall rules
• Rate limiting
• IP or country blocking

A simpler configuration is usually easier to operate and troubleshoot.

Test after updates

After updating WordPress, a plugin, or a theme:

• Clear all active cache layers.
• Test important pages.
• Check the browser console.
• Review recent errors.
• Confirm that forms and interactive elements work.
• Monitor performance for unexpected changes.

If an issue begins immediately after an update, test a rollback on staging to confirm whether the update caused the problem.

Need help?

Contact Support if:

• You cannot identify which plugin, theme, or feature causes the issue.
• The Performance Plugin cannot connect to EDGE.
• Performance Plugin settings cannot be saved.
• A security plugin appears to block required communication.
• The problem remains after disabling overlapping features.
• The website remains broken after clearing all cache layers.
• You need help interpreting logs or request behavior.

Include:

• The affected domain
• The affected URL or feature
• The approximate timestamp
• The steps required to reproduce the issue
• The plugin or theme name and version
• The WordPress and PHP versions
• Screenshots or recordings of the problem
• Browser-console errors
• Relevant plugin, PHP, access, or server logs
• The troubleshooting steps already completed
• Any recent updates or configuration changes

This information helps Support reproduce and investigate the issue.

Where to go next

• Review Performance Plugin troubleshooting for connection, settings, optimization, and processing issues.
• Follow the guide to configure Performance Plugin settings before changing optimization features.
• Review CSS and JavaScript optimization for minification, concatenation, exclusions, and testing guidance.
• Review automatic image optimization before changing image-processing tools.
• Use Access Logs to review recent HTTP requests.
• Review cache management when the issue involves stale content or unexpected cache behavior.
• Follow Cache not working when requests are not being cached as expected.
• Follow Images not loading when image delivery is affected.