I upgraded to concrete 5.6.2.1 today. I am having trouble adding new blocks. I get the following error message. I can update existing blocks but cannot add new. Suggestions?

Warning: require_once(/home4/eastvie5/public_html/updates/concrete5.6.2.1_updater/concrete/models/json.php) [function.require-once]: failed to open stream: No such file or directory in/home4/eastvie5/public_html/updates/concrete5.6.2.1_updater/concrete/core/libraries/loader.phpon line 48

Fatal error: require_once() [function.require]: Failed opening required '/home4/eastvie5/public_html/updates/concrete5.6.2.1_updater/concrete/models/json.php' (include_path='/home4/eastvie5/public_html/libraries/3rdparty:/home4/eastvie5/public_html/updates/concrete5.6.2.1_updater/concrete/libraries/3rdparty:.:/usr/lib64/php:/usr/share/pear') in/home4/eastvie5/public_html/updates/concrete5.6.2.1_updater/concrete/core/libraries/loader.phpon line 48