Skip to main content
Version: 1.x

Plugin Conflicts

Plugin conflicts are one of the most common causes of issues with WCPOS. When other WordPress plugins interfere with WooCommerce or WCPOS functionality, you may experience crashes, performance problems, or unexpected behaviour.

Signs of Plugin Conflicts​

You may have a plugin conflict if you experience:

  • Fatal errors - "There has been a critical error on this website"
  • Performance issues - Slow loading, timeouts, or high server load
  • Functionality problems - Features not working as expected
  • Data sync issues - Products, orders, or customers not syncing properly
  • Payment gateway problems - Checkout failures or payment processing errors

Before You Start: Use a Staging Site​

Important

Never troubleshoot plugin conflicts on your live site. Always use a staging environment to avoid disrupting your business operations.

What is a Staging Site?​

A staging site is an exact copy of your live website where you can safely test changes without affecting your customers. Most modern hosting providers offer staging environments as a standard feature.

If Your Host Doesn't Offer Staging​

If your hosting provider doesn't offer staging sites, consider switching to a host that does. This is a standard feature nowadays and essential for:

  • Safe plugin/theme testing
  • WordPress updates
  • Troubleshooting issues
  • Development work

Recommended hosts with staging:

  • WP Engine
  • SiteGround
  • Kinsta
  • Cloudways
  • Many others

Step 1: Check for Fatal Errors​

If you're experiencing crashes or critical errors, start by checking the error logs:

  1. Check WCPOS Logs - Open the Logs screen in WCPOS for any error messages
  2. Check Fatal Error Logs - Follow the Critical Error troubleshooting guide to find detailed error messages
  3. Note the error details - Look for plugin names or file paths mentioned in the error

If you find a fatal error that mentions a specific plugin, that's likely your culprit. You can disable that plugin and test if the issue is resolved.

Step 2: The Plugin Elimination Method​

If there are no fatal errors in the logs, or you want to identify performance-related conflicts, use this systematic approach:

2.1 Create a Baseline​

  1. Access your staging site
  2. Test the problematic functionality - Note exactly what isn't working or is slow
  3. Record performance metrics - If it's a performance issue, note execution times from the Logs

2.2 Disable All Plugins (Except Essential Ones)​

Keep these plugins active:

  • WooCommerce
  • WooCommerce POS (WCPOS)
  • WooCommerce POS Pro (if you have it)

Disable everything else:

  1. Go to WP Admin > Plugins
  2. Select all other plugins
  3. Choose "Deactivate" from the bulk actions dropdown
  4. Click "Apply"

2.3 Test the Issue​

  1. Clear any caches - If you use caching plugins, clear all caches
  2. Test the problematic functionality - Does it work now?
  3. Check performance - Are execution times improved?

If the issue is resolved: You have a plugin conflict. Proceed to Step 2.4.

If the issue persists: The problem is likely not a plugin conflict. Consider:

  • Server resource issues (see Server Performance)
  • Theme conflicts (see Step 3)
  • Core WordPress/WooCommerce issues

2.4 Enable Plugins One by One​

Now you need to identify which plugin is causing the conflict:

  1. Enable one plugin - Start with the most essential ones first
  2. Test the functionality - Check if the issue returns
  3. If no issue - Enable the next plugin and test again
  4. If the issue returns - You've found the conflicting plugin!

Plugin Priority Order (enable in this order):

  1. Security plugins - Wordfence, Sucuri, etc.
  2. SEO plugins - Yoast, RankMath, etc.
  3. Performance plugins - Caching, optimisation
  4. Payment gateways - Stripe, PayPal, etc.
  5. Other WooCommerce extensions
  6. General WordPress plugins

2.5 Document Your Findings​

When you identify the conflicting plugin:

  1. Note the plugin name and version
  2. Document the specific issue it causes
  3. Check if there's an updated version available
  4. Look for alternative plugins that provide similar functionality

Step 3: Check for Theme Conflicts​

While themes rarely affect WCPOS (since it uses its own interface), they can sometimes cause issues with:

  • Checkout processes (if using web checkout gateway)
  • Admin area functionality
  • API responses

Test with a Default Theme​

  1. On your staging site, switch to a default WordPress theme:
    • Twenty Twenty-Four
    • Twenty Twenty-Three
    • Twenty Twenty-Two
  2. Test the problematic functionality
  3. If the issue is resolved - Your theme has a conflict
Theme Impact

Themes are much less likely to cause WCPOS issues compared to plugins. The POS interface runs independently of your theme. However, themes can affect:

  • WooCommerce checkout pages
  • WordPress admin functionality
  • REST API responses

Step 4: Resolving Plugin Conflicts​

Once you've identified the conflicting plugin, you have several options:

Option 1: Update the Plugin​

  1. Check for updates - The conflict may be fixed in a newer version
  2. Update the plugin on your staging site first
  3. Test thoroughly before updating on live site

Option 2: Find an Alternative​

  1. Research alternative plugins that provide the same functionality
  2. Test alternatives on your staging site
  3. Migrate settings if switching plugins

Option 3: Contact Plugin Developer​

  1. Report the conflict to the plugin developer
  2. Provide detailed information:
    • Plugin versions involved
    • WordPress and WooCommerce versions
    • Exact error messages or behaviour
    • Steps to reproduce the issue

Option 4: Custom Solution​

For essential plugins that can't be replaced:

  1. Contact a WordPress developer to create a custom fix
  2. Consider plugin-specific hooks to disable conflicting functionality
  3. Use conditional logic to disable the plugin on POS-related pages

Common Conflicting Plugin Types​

High-Risk Plugin Categories​

Security Plugins:

  • Can block API requests
  • May interfere with authentication
  • Often have aggressive firewall rules

Caching Plugins:

  • Can cache API responses inappropriately
  • May interfere with real-time data
  • Can cause stale data issues

SEO Plugins:

  • Heavy plugins can slow down admin area
  • May add unnecessary database queries
  • Can interfere with REST API responses

Page Builders:

  • Often load heavy scripts in admin area
  • Can conflict with WooCommerce admin pages
  • May interfere with checkout processes

Membership/Restriction Plugins:

  • Can block API access
  • May interfere with user authentication
  • Can restrict access to required resources

Lower-Risk Plugin Categories​

Contact Forms: Usually don't interfere with WCPOS Social Media Plugins: Rarely cause conflicts Analytics Plugins: Generally safe unless very heavy Basic Content Plugins: Usually compatible

Prevention Tips​

Regular Maintenance​

  1. Keep plugins updated - Always use the latest versions
  2. Remove unused plugins - Don't just deactivate, delete them
  3. Test updates on staging before applying to live site
  4. Monitor performance regularly using Server Performance metrics

Plugin Selection Best Practices​

  1. Choose reputable developers - Check reviews and update frequency
  2. Avoid redundant functionality - Don't install multiple plugins that do the same thing
  3. Read compatibility information - Check if plugins are tested with WooCommerce
  4. Start with minimal plugins - Add functionality gradually as needed

Getting Help​

If you're unable to resolve the plugin conflict:

For Pro Users​

Pro Support

Pro users receive priority support for plugin conflict resolution. Our team can help identify and resolve conflicts for you.

Community Support​

When Contacting Support​

Please provide:

  1. List of active plugins with versions
  2. WordPress and WooCommerce versions
  3. Detailed description of the issue
  4. Steps you've already tried
  5. Error messages from logs
  6. Server performance metrics if relevant