This looks to be a server configuration issue, the server is not working with paths correctly and is alo being onconsistant.
I added code to the webassist/file_manipulation/helperphp.php file to see what path the files is being uploaded to
in some instances it reports uploading to C:\php\uploads\ and in others to C:\uploads\:
it should be uploading to the site root, but some reason, the server is not returning that path.
even using the getcwd() command, which should return the path for the file being executed is returning the c:\php path. You will need to work with the host to determine why paths are not working correctly.