Prova così
Codice PHP:
var_dump($_FILES);
echo 'File exists: '.file_exists($_FILES['File1']['tmp_name']).'
';
echo 'Destination directory exists '.file_exists('/websites/symlinks/demo/Uploads/Image').'
';
$written=file_put_contents('/websites/symlinks/demo/Uploads/Image/testfile.test', '');
echo $written!==false?'File could be written':'File could not be written';