I just encountered this bug today, I was just using my rod of recall to head back after clearing the lost crypt (for the necro unlock). Unfortunately the game just hung at "loading level" so I had to forcibly quit it.
When I restarted it, I had to clear everything again. But this time when I tried to recall, it put me at the start of the fortress before a locked door, with lore pop-up and without any beast in sight to defeat.
My character for what it's worth: https://te4.org/characters/115263/tome/ ... 1afa8764d6
Sadly this has been one of the most successful characters I've had...
-edit- i didn't have steam cloud saves enabled