Whenever I try to add a block I get this error message:

Warning: require_once(/home/nickcurry/zplususa.org/updates/concrete5.6.2.1_updater/concrete/models/json.php) [function.require-once]: failed to open stream: No such file or directory in /home/nickcurry/zplususa.org/updates/concrete5.6.2.1_updater/concrete/core/libraries/loader.php on line 48

Fatal error: require_once() [function.require]: Failed opening required '/home/nickcurry/zplususa.org/updates/concrete5.6.2.1_updater/concrete/models/json.php' (include_path='/home/nickcurry/zplususa.org/libraries/3rdparty:/home/nickcurry/zplususa.org/updates/concrete5.6.2.1_updater/concrete/libraries/3rdparty:.:/usr/local/lib/php:/usr/local/php5/lib/pear') in /home/nickcurry/zplususa.org/updates/concrete5.6.2.1_updater/concrete/core/libraries/loader.php on line 48