Troubleshooting Disk Page Cache permission warnings

When you turn on Enable Disk Page Cache (the local disk cache, also called the fallback cache), Super Page Cache stores copies of your pages on your own server as a backup to Cloudflare. To set this up with the default method, the plugin needs to:

• Add the line define('WP_CACHE', true); to your wp-config.php file.
• Create the advanced-cache.php drop-in file inside your wp-content directory.

If your host blocks writes to these locations, the plugin shows a setup warning such as The file wp-config.php is not writable or The directory wp-content is not writable.

📝 Note: This warning affects only the local disk cache. Your Cloudflare edge caching keeps working normally whether or not Disk Page Cache is enabled, so your pages are still cached across Cloudflare's network.

You can resolve it in one of the following ways.

Switch the fallback cache to cURL mode

Enabling cURL changes how the plugin builds the local cache so that it no longer uses the advanced-cache.php drop-in or the WP_CACHE line in wp-config.php. If those are the only writes your host is blocking, switching to cURL lets you keep the disk cache without editing wp-config.php.

1. Go to Super Page Cache → Advanced → Cache.
2. Enable Use cURL.
3. Click Save Settings.

cURL mode still writes cached files to your server, so it does not help if your host blocks all writes inside wp-content. For more detail, see Should I enable the cURL mode for Fallback Cache? and the Super Page Cache settings reference.

Leave Disk Page Cache disabled and rely on Cloudflare

If you cannot change these permissions, leave Enable Disk Page Cache turned off and continue using Enable Cloudflare CDN & Caching. You lose only the local disk fallback layer — edge caching on Cloudflare is unaffected.

If you want the disk cache: what to ask your host

If you need the local disk cache and cURL mode is not enough, contact your hosting provider or server administrator and ask them to:

• Add the line define('WP_CACHE', true); to your wp-config.php file, and
• Allow WordPress and Super Page Cache to create or update the wp-content/advanced-cache.php file.

Once these changes are in place, return to the plugin settings and enable Enable Disk Page Cache again.