Changing Media Thumbnails

[Efficient_Good_5784]

Easiest thing would be to just delete the thumbnaila from your server. This will cause Jellyfin to show a blur since it can't find the source. Though you have to make sure to disable all episode image metadata sources so that they don't come back.

Another thing you could do is use CSS to cover up the episode images.

edit:
The following CSS code will hide episode images from the episode lists and replace them with solid-black. You will still get episode images however if you click on an episode to fully open its details.

Code:

.listItemImage.listItemImage-large.itemAction.lazy {
  background-image: none !important;
  background-color: black;
}