not sure what happened... just took a look at the site and now its not loading and instead displaying these errors below:

Warning: require_once(/home/xxx/xxx.com/concrete/config/../libraries/cache/abstract.php) [function.require-once]: failed to open stream: No such file or directory in /home/xxx/xxx.com/concrete/libraries/loader.php on line 35

Fatal error: require_once() [function.require]: Failed opening required '/home/xxx/xxx.com/concrete/config/../libraries/cache/abstract.php' (include_path='.:/usr/local/php5/lib/php:/usr/local/lib/php:/home/xxx/xxx.com/libraries/3rdparty:/home/xxx/xxx.com/concrete/config/../libraries/3rdparty') in /home/xxx/xxx.com/concrete/libraries/loader.php on line 35


HELP!