I can't activate wp super cache after moving from development server to live. I've seen some other people have similar problems due to the old url being referenced somewhere. One suggestion involved un/re-installing plugin, which I did.
However I got a new error after that on the wp super cache settings page:
Error: Sample WP-Cache config file (/home/sites/[MYDOMAIN]/public_html/demo/wp-content/plugins/wp-super-cache/wp-cache-config-sample.php) does not exist.Verify you installation. Cannot continue... fix previous problems and retry.
That's referencing the old location, the current one is
ie, not in the 'demo' subfolder (which was mapped as a subdomain using the host's cpanel.)
I've confirmed via ftp the files (along with the rest of the plugin) are all installed in the new location, but obviously that's no use if the plugin is looking in the wrong place.
Some solutions to similar problems have suggest editing the URL in advanced-cache.php but that file is totally blank.