torrent files cannot open

Hi,I recently installed transmission-daemon on my NAS.But I noticed that evertime I restarted my NAS ou simple transmission-daemon, all of my torrents got the .torrent.added extension.And so, any them resume where they were left when shutting down just because of this .added extension.But after I searched, many sites can not be opened by Google??? I don’t know why even though I got a page that tells how to convert torrent to MP4(](, but when the program called me to load my torrent file, I found my folder was empty?? When I log out, the files can appear? wtf? anyone uses this? did I do something wrong? Could someone give me some help?
Thank you!