(I know it’s not called MU anymore, but lets just roll with it.)
At the time of this article I was working with:
WP-Super-Cache version: 0.9.9.6
WordPress version: 3.0.1
I fought for over an hour trying to get WP-Super-Cache working properly on my WordPress install, I hope that this can help you fix yours sooner than I did.
- I did have to download the plugin manually. Don’t attempt to use the built in plugin installers because they’ll put it in the wrong place.
- When you install the plugin, you’ll need to put it into the /wp-content/mu-plugins/ directory. You don’t install anything into the /wp-content/plugins/ directory.
- Copy the wp-cache-config-sample.php from the /wp-content/mu-plugins/wp-super-cache/ directory into the /wp-content/ directory. Rename it to wp-cache-config.php. On line 19, change the path from “/plugins/wp-super-cache/” to “/mu-plugins/wp-super-cache/”.
- Copy the advanced-cache.php from the /wp-content/mu-plugins/wp-super-cache/ directory into the /wp-content/ directory. On lines 8 and 9, change ‘CACHEHOME’ to the path of your wp-super-cache directory where the path is the complete path from the root. Mine was ‘/home/<site name>/public_html/wp-content/mu-plugins/wp-super-cache/’
That should help you along your way. WP-Super-Cache was very good at guiding me through the troubleshooting process. There was guidance on editing .htaccess files and setting permissions.
I used the FileZilla ftp client to handle the file transfers and file editing. (I actually use FileZillaPortable) You can view hidden files by clicking on Server -> Force showing hidden files from the menu bar; this allows you to see the .htaccess files. You can also change file and folder permissions from inside FileZilla just as WP-Super-Cache asks you to.
Another semi-helpful post I found was Austin Gulati’s Using the WP Super Cache Plugin.