The following folders have to be chmod-ed to 777 (readable/writable/executable by all users) for wp-cache to work:
wp-content
wp-content/cache
You can do this from your host’s cpanel or webftp.
If it doesn’t work you can try chmod-ing these too:
wp-content/plugins
wp-content/plugins/wp-cache
Create a file named unlink.php in your wp-content folder with this in it:
<?php unlink("cache/wp_cache_mutex.lock"); ?>
Then access it from the browser: http://yoursite.com/wp-content/unlink.php
It will unlink the cache/wp_cache_mutex.lock, so you can delete the folder. You can delete unlink.php afterwards.
Create a file named symlink.php in your wp-content folder with this in it:
<?php symlink("plugins/wp-cache/wp-cache-phase1.php","advanced-cache.php"); ?>
Then access it from the browser: http://yoursite.com/wp-content/symlink.php
It will create your symlink. You can delete it afterwards.
