The selected file could not be uploaded, because the destination is not properly configured
This "feature" has bitten me before. It's one of those annoying Drupal things which would be fine if the error message wasn't so misleading.
What's happening is that file_copy() calls file_create_path()
<?php
function file_copy(&$source, $dest = 0, $replace = FILE_EXISTS_RENAME) {
$dest = file_create_path($dest);
?>While file_copy() doesn't declare that it only works in the Drupal folders - file_create_path is clear about this.
