The Restless Reader achievement (to read 40 lorebooks) has been unachievable for all 392 days since it was introduced, making it impossible to get 100% in the Adventures category of achievements!
Even very thorough community efforts (e.g. see https://bit.ly/3XoOjVK) have found it impossible to discover more than 34. Furthermore, new lorebooks were added to the just-launched Battle of the Bands tavern brawl, but these do not advance the achievement!
I know not everyone cares about achievements, but for some of us achievements are very important for having goals to work towards in the game. It’s extremely discouraging, having invested a lot of effort to achieve 99% in a category, for one achievement to just be unachievable for so long with no comment whatsoever from the team.
In general, the Hearthstone team has actually been pretty good at fixing broken achievements, so I imagine this one might be quite involved to “fully” fix in the sense of making all the originally intended lorebooks spawn properly. But if a “full” fix is never going to get prioritized by the team anyway, I’d like to propose some more practical fixes that should be much simpler to at least stop the achievement from just never being achievable:
- Allow re-reading a lorebook to progress the achievement, rather than needing to find 40 distinct ones (which is currently impossible). The achievement wording does not actually state that the lorebooks need to be distinct/different in the first place.
- Lower the count of the final part of the achievement down to 34 (or 32) instead of 40. Even this is still incredibly challenging even at this lower number as many lorebooks are extremely difficult to spawn and require a lot of research (see above thread).
- Make the lorebooks in the new Battle of the Bands tavern brawl count towards the achievement! This fix would need to be implemented before July 5 since that’s when the brawl’s 2nd run ends. Even though it’s unideal that completing the achievement would only be possible in a limited-time way, still better than it just never being achievable! And maybe the tavern brawl could occasionally be brought back (like several tavern brawls are) so periodically folks would get another chance to complete the achievement.
- On the unlikely off-chance that the achievement is actually achievable, just so difficult that the community hasn’t figured out how, it would be great if this could at least be acknowledged by the team, and perhaps Celestalon could leave a small hint or two like he used to for the mystery cardback achievements that were tough.
It would be so appreciated by many of us who pour a lot of effort into achievements if we could get some sort of fix, or at the bare minimum some sort of acknowledgement/response. Without that, it’s very discouraging to continue playing the game when some achievements are just indefinitely never getting fixed or commented on in any way.
P.S. If you’re someone who also cares about this, I’d encourage you to post a report about it yourself too (but not multiple like myself). I suspect that with a forum of reports this large, there’s some automated aggregation, and more people reporting the same bug (please include “Restless Reader” in the title) may increase the chance that a real human being actually looks at it at some point 
