The Page Cache add-in file advanced-cache.php is not a W3 Total Cache drop-in

Hello @teamwavelength

I am sorry about the issue you are experiencing and I am happy to assist you with this.
At some point, you’ve had some other caching plugin installed that has drop-in files the same names as W3 Total Cache does.
you should manually delete that file from the wp-content folder as apparently something is blocking the removal via the wp dashboard.
Once that file is deleted W3 Total Cache will drop-in its’own advanced-cache.php
Thank you!

Unfortunately, that doesn’t work. I have manually deleted the advanced-cache.php file multiple times and the error always recurs.

Hello @teamwavelength

Are any other caching plugins installed?
Can you please try to completely remove W3 Total Cache and re-install?
1. Purge Cache
2. Deactivate and Delete Plugin
3. Check .htaccess File (make backup)
W3TC will create many directives in the .htaccess file to control caching behavior. Each section will start and end with comments like “#BEGIN W3TC Page Cache core” and “#END W3TC Page Cache core”.
Ensure that no residual entries are leftover in your .htaccess file after deleting the plugin.
4. Delete wp-content files and folders
– cache folder
– w3tc-config folder
– object-cache.php (if exists)
– advanced-cache.php (if exists)
– dbcache.php (if exists)
– upgrade folder
– delete w3-total-cache folder in wp-content/plugins/ (if exists)
5. Delete Cached Files from CDN (if using CDN)
Besides deleting all the relevant files, if you use CDN then ensure to purge the cached content from your CDN. This is necessary when you enabled the minify option in W3TC settings. You should delete the minified and combined scripts and CSS files from your CDN server to avoid the site breaking on the browser.
6. Go to your wp dashboard and re-install W3 Total Cache
Thank you!