title: Can not change permissions on FTP for files created with PHP copy
body: <p>I have a script that uses the <code>copy</code> function of PHP to copy files to my server. When I log into my server via FTP I can't delete them anymore, as the permissions are set to 644. But when I try to change the permissions directly at the FTP, I get a "Operation not permitted" error. </p>
  
  <pre><code>NOOP
  200 NOOP command successful
  SITE CHMOD 777 /test2/2016-07-19/13739536_1750492681870132_416621053_n.jpg
  550 CHMOD 777 /test2/2016-07-19/13739536_1750492681870132_416621053_n.jpg: Operation not permitted
  </code></pre>
  
  <p>Normally I can change the permissions on my server without any problems. Via SSH it is also not working. Does it have to do something with the permissions of the original file?</p>
  
  <p>Thanks for your help!</p>