content_form.class.php File not complete solution

Play phpcms from how many will encounter this problem,
According to the error prompt we can find is due to the content_form.class.php file is incomplete, there are many articles on the web that is to replace this file with the local, but as long as a newer cache problem will appear, not root, decisively discarded.
This problem, the general use of FTP upload files, the file code is missing, so that the code is not complete, as long as the missing files to find, and then upload the good.
.. /phpcms/modules/content/fields/video/form.inc.php
It is the error caused by the incomplete file, which is the real culprit. All we have to do is replace this file with a "binary" transfer mode if uploading with FTP is recommended.