I had submitted a formal bug report on this issue with a lot of detail. I did hear back from a tech support person (very nice btw), but they gave me unfortunate news. Larian believes this particular bug is only due to the presence of mods and that non-modded games will not experience this problem. At least that's what they said. They then gave various instructions on how to remove mods.
Imagine my surprise as I don't even know 'how' to mod Baldur's Gate 3. (I am a PC user). But, because Larian is of the mind that this crash only occurs for modded games, it's unlikely it will ever get attention from a patching perspective unless they change their mind. So while I do not use mods personally and still get the crash, let me ask you @ledouze, do you use mods?
For reference:
The moment I cross out of Lower City to Wyrm's Crossing via the Basilisk Gate entrance, it loads fine. When I try to go back to the Lower City immediately after this, it crashes. I can save and run around in the Lower City just fine, and reload saves just fine. This crash only occurs if I go to Wyrm's Crossing and then try to get back into the Lower City I've tried various iterations of DX 11 and Vulkan I've tried dismissing companions I've tried finding dead people with more than 0hp (though in the Lower City that's a chore and some places are off limits like the Foundry that's now in ruins) I've tried older saves (like way older) and the crash still occurs, whether or not I've fought Gortash or his guards I've tried lowering graphics settings I've tried reinstalling the game
In short, nothing works. But again, Larian believes this is a mod issue so it looks like I'll be unable to complete the game.
