There are a few possible reasons why your Raspberry Pi 3 might be hanging when you view the download film list in the media library.
The number of films in the download list is too large. The Raspberry Pi 3 is a relatively low-powered device, and it can struggle to manage large lists of files. If you have a large number of films in your download list, the Raspberry Pi 3 may not be able to keep up and may hang.
The films in the download list are stored on a slow storage device. The Raspberry Pi 3 has a limited amount of built-in storage, and it can be slow to read and write files to this storage. If your films are stored on a slow storage device, such as a USB drive, the Raspberry Pi 3 may not be able to load the download list quickly enough and may hang.
The media library software is not optimized for the Raspberry Pi 3. Some media library software is not optimized for the Raspberry Pi 3, and it can cause the device to hang when loading large lists of files.
Here are a few things you can try to fix the problem:
Reduce the number of films in the download list. If you have a large number of films in your download list, try removing some of them to see if that resolves the issue.
Move the films in the download list to a faster storage device. If your films are stored on a slow storage device, try moving them to a faster storage device, such as an SSD.
Try using a different media library software. Some media library software is not optimized for the Raspberry Pi 3, so try using a different media library software to see if that resolves the issue.