So I have been using the latest version in 1.10.x and came across a slightly annoying bug. While you CAN set up separate background images for different quests, if you only have one selected (one quest line with a custom background) after clicking on that one in the main list where it kinda shows a preview then all other quest lines will now show the same background.

This was the other 1.12 bug I was talking to you about.