Upgrading to Concrete 4.0
PermalinkFatal error: Zend_Cache::require_once() [function.require]: Failed opening required 'Zend/Cache/Backend/File.php' (include_path='.:/usr/lib/php:/usr/local/lib/php:/home/php') in /concrete/libraries/3rdparty/Zend/Cache.php on line 132

but if some of those are missing, then you may just want to reupload the entire core just to make sure.
if that doesn't do it, then it could be a permissions issue. make sure all those files are at readable and executable by the server
If you have access to the database try to set the Flag ENABLE_CACHE in CACHE table to 0 and clean the cache directory in files/cache via ftp.
concrete/libraries/3rdparty/Zend/Cache/File.php
Is it possible that the FTP client in question is not uploading files a certain level deep?
There is File.php in both
concrete\libraries\3rdparty\Zend\Cache\Backend
and
concrete\libraries\3rdparty\Zend\Cache\Frontend
but none in the Cache dir itself.