Well, I saved just before I went down there, but yes, also tried with another household, but same thing.
It's just like it's a tomb without any adventure to it. Although I have the ancient library adventure. But just before I get the book, the note with the "tomb fully explored" comes up and the adventure goes away from my "journal" like it was finished there.
But I could maybe try with a new person again just to be sure. And if I'm lucky, then try to swap the book or something.
EDIT: Nope, even with a whole new sim, the adventure goes away and I think that's why the chest doesn't light up.
[Edited for punctuation and typos. Please use Preview before posting to avoid excessive editing. Thanks! -Pam]
[Second edit for profanity. Please refain from the use of any type of profanity on this forum. -Pam]