I would state that your trying to upload a file larger than your server's PHP max upload hense it is dropped. You are not going to find the file. PHP will drop a file from the server which is larger than its max upload size and if your video is over say 2mb in most cases you can not upload it without altering your server's PHP settings.
You need to edit your php.ini file and specify higher amounts for max_execution_time, memory_limit, max_upload_filesize etc to allow what you want and save that then reboot your server. You can then check your phpinfo to see that they have indeed been loaded and then try it.