TBH the entire religion quest line seems broken.
First I got the quest to recover the Relic from a museum. So I get back with the Relic but the NPC wouldn’t accept the quest. I still haven’t completed it. Despite that the NPC gave me another quest “Recover Priest’s Diary”. I hadn’t actually had the diary yet but I spoke to the NPC again and it acted as if I had it and I was able to complete the quest (I didn’t even leave the shelter yet lol). Then it gave me 2 new quests, “Prison Visionary” which I haven’t tackled yet, and “Investigate Cult”. “Investigate Cult” seems completely stuck. I killed the wraith, found the hidden basement, murdered everything in the basement including the Blood Sacrifice, picked up the Etched Human Skull and went back. The NPC won’t accept it. I’m actually mad. I also noticed the Relic is gone, nowhere to be found. None of the NPCs have it either, and the “Find Relic” quest remains active.
If it doesn’t break your save itself it very well may break various things inside of it, even more so if you update to one of the experimentals.
For just one example of the latter, a post 0.E experimental (at least I think it was after) gave everything an item length and volume sizes for in specific clothing pockets. Your total capacity no longer fuses together and is instead individual pockets to be filled.
Usually updating from a stable build to a future stable build should not break an existing save.
But it’s always a good practice to make a backup of your save folder and/or of your whole cataclysm folder in case you have to return to a previous version.
There are a lot of new things and others that have changed between versions, so you might take a moment to adjust to the “new” game. Some are annoying, others are helpful.
On the other hand… if you don’t update, you’ll have to live with that bug you’ve described, as there’s no way to fix something like that without updating.