I can't install cMandrill on my site, I have joomla 2.5.8, this message show up:

Warning: require_once(__DIR__/autoloader/autoloader.php) [function.require-once]: failed to open stream: No such file or directory in /home/content/26/8083426/html/website/tmp/install_52deaf6c8def0/libraries/compojoom/libraries/compojoom/include.php on line 18

Fatal error: require_once() [function.require]: Failed opening required '__DIR__/autoloader/autoloader.php' (include_path='.:/usr/local/php5/lib/php') in /home/content/26/8083426/html/website/tmp/install_52deaf6c8def0/libraries/compojoom/libraries/compojoom/include.php on line 18