Troubleshooting
A page looks broken after enabling a setting
- Click Clear Cache and reload the page — a stale cached copy from before your change is the most common cause.
- If it's still wrong, identify the most recently changed setting and turn it off, then clear the cache again to confirm that was the cause.
- Check the notes below for the settings most likely to cause a visible issue.
Settings most likely to need attention if something looks wrong
| Setting | Tab | What to check |
|---|---|---|
| Load Combined CSS Asynchronously | CSS | Causing a flash of unstyled content? You need Critical CSS filled in — see CSS Optimisation. |
| Combine JavaScript Files / Delay JavaScript Until User Interaction | JavaScript | A feature stopped working? Find its script's handle or filename in your browser's developer tools and add it to the exclude field. |
| Disable WooCommerce Scripts on Non-Shop Pages | Advanced | My Account page (orders, downloads) look unstyled? This is the setting — check it isn't excluding those pages incorrectly for your theme. |
| Cache Pages for Logged-in Users | Caching | Seeing content meant only for logged-in users appear for anonymous visitors? Turn this off and clear the cache. |
| WordPress Heartbeat: Disable | Advanced | Autosave or "someone else is editing this" notices stopped working? Switch back to Optimise instead of Disable. |
"Add define('WP_CACHE', true) to your wp-config.php" notice won't go away
The plugin tries to add this automatically when activated. If your hosting doesn't allow it to write to wp-config.php, you'll see this notice with a Retry automatically button. If retrying doesn't clear it, add the line yourself:
define( 'WP_CACHE', true );
Place it above the /* That's all, stop editing! */ line near the bottom of wp-config.php. Your site caches correctly either way — this notice is about reaching the fastest of three delivery methods, not about caching being broken.
Cache directory not writable
If you see a notice that wp-content/cache/ isn't writable, your hosting needs that directory (and the plugin's subfolder within it) set to permission 755. Most hosts allow this by default; shared hosting with unusually strict permissions occasionally needs it set manually via your file manager or hosting support.
A specific plugin or theme feature stopped working
Most compatibility issues trace back to combined CSS/JS. Add the affected stylesheet or script to the Exclude Handles or Filenames field on the relevant tab (CSS or JavaScript) rather than turning combining off entirely — this keeps the optimisation for everything else while carving out the one exception you need.
Before uninstalling
Clear your cache manually first, and if you've been using the automatic WP_CACHE setup, you may want to remove define( 'WP_CACHE', true ); from wp-config.php yourself afterward — uninstalling the plugin doesn't automatically remove that line.