Server Version#:1.19.4.2935-79e214ed
Player Version#:android, Roku
I posted this problem here over a year ago. Before, if I deleted a movie from my collection and it’s folder contains a .srt (subtitle) file or a folder (movie poster) file with the movie in the same file the movie will be deleted but the file will remain due to the .srt file within. I won’t see the movie in PLEX but I do see the file in Microsoft Explorer or my ReadyNAS Ready Cloud.
After a year of searching I found a free program called Tree Size Free.
You can delete/mass delete your files easily! It’s self explanatory.
You can use it on your computer for your NAS also. Good luck!