FTP download failure

Using Filezilla to download my WP-includes folder, wp-config and .htaccess to my computer for backup. Has worked in the past but this time I get only 1831 successful downloads and 2571 failed. Message is “failed to open ////.jpg” for writing” etc.

Seems to be all from either Uploads or Updraft. It doesn’t even create a folder or start downloading Themes.

Any ideas? Like I said, it all seemed to work OK when I did it at the end of July.

Thanks.