The application allows you to convert your videos to the known file formats like MOV, WMV, MP4, 3GP, FLV, MKV, MP3. Simply open the files you have, then convert them to MP4 or FLV and you should have the possibility of uploading them to YouTube. I have tested the application and it works as it should. I have converted a sample movie to MP4 format, then accessed YouTube manually and uploaded the file. Everything was good.
Try downloading the latest version of the software to prevent other errors in the process: http://www.iskysoft.com/video-editor-windows.html