Hello, I recently installed WordPress MU and Buddypress and I see that it's time to upgrade to MU 2.8.3. However, when I hit upgrade, this is what shows up:
Downloading update from http://mu.wordpress.org/wordpress-mu-2.8.3.zip.
Unpacking the update.
Warning: copy(wp-content/upgrade/wordpress-mu-2.8.3/wordpress/wp-admin/includes/update-core.php) [function.copy]: failed to open stream: No such file or directory in /wp-admin/includes/class-wp-filesystem-direct.php on line 131
Could not copy files.
How can I fix this problem?