Fix WP Super Cache Errors: No Cached Pages

Caching of your wordpress files is very important to reduce the server and database load, especially in shared hosting scenarios. WP-Supercache, the next generation of WP-Cache is a powerful wordpress caching plugin.

WP-Cache 2 is a popular plugin that caches the pages of your WordPress blog and delivers them without accessing the database, but it still means loading the PHP engine to serve the cached files; WP Super Cache gets around that by generating html files that are served without invoking a single line of PHP!

WP-Cache had problems working on this blog and always ended up bringing the site down. After this site overloaded servers, I had to try installing WP-supercache to see if might work. The installation and activation went without a hitch, the blog was loading fine, but no pages were being cached!

WordPress Super Cache Not Working?

I looked up the Troubleshooting page and here is the checklist.

1. Is wp-content writable by the web server?
   Yes. Looked for file permissions. All OK
2. Is there a wp-content/wp-cache-config.php ?
   I deleted it earlier as preinstallation task (earlier installed by WP-cache). This was created there when plugin activated.
3. Is there a wp-content/advanced-cache.php ?
   I was unable to delete this linked file via FTP as a preinstallation task (earlier installed by WP-cache). But it was still there.
4. Make sure the following line is in wp-config.php define( 'WP_CACHE', true );
   This entry was deleted from wp-config.php as a preinstallation task (earlier installed by WP-cache) and now it was recreated back in the same place.
5. Try the Options->WP Super Cache page again and enable cache.
   Done. OK. But the status is still same.
6. Look in wp-content/cache/supercache/…
   Something wrong. No files there. No folder there.
7. Anything in your php error_log?
   No.
8. If your browser keeps asking you to save the file…
   Well Super Cache compression was disabled by default in the options and browser asked nothing.
9. The plugin does not work when PHP’s safe mode is active.
   Ok. No problems.
10. Your blog can be viewed with and without the “www” prefix.
    Blog set to view as www. No problem there.

Fix WP-Super-Cache Problems

Then I went about checking and here are the few tips that worked for me, and might work for you too.

1. No Supercache Folder – In #6 supercache folder was missing, so I had to manually create the folder as it was not there. I used FTP to login to my server using Filezilla and created wp-content/cache/supercache/. But still not working.

2. Change Settings – I tried working in HALF ON (Super Cache Disabled) mode, Super Cache Compression on and off mode, checked the .htaccess files for correct mod_rewrite rules (important to check!), but nothing worked.

2. Deleting advanced-cache.php. Then I realized that in #3, I was unable to delete advanced-cache.php. Though I believed the installation had rewritten on the linked file, it might have not.

The ealier wp-cache file was linked to wp-cache/wp-cache-phase1.php
but the supercache file should link to wp-super-cache/wp-cache-phase1.php

I thought this was the problem. But I was unable to delete it via FTP. So I used my newly acquired SSH skills and use PuTTY to get in and delete the file.
cd wp-content
rm advanced-cache.php

and the file was finally deleted. Disable and Activate the plugin, it generated a new advanced-cache.php with the new shortcut. I could have also tried
ln -s plugins/wp-super-cache/wp-cache-phase1.php advanced-cache.php

Guess what…. it started to work!!!

If that does not help you, look up the wordpress forums for more support.