I am having this same issue as well - however, deleting the Larian Studio / Steam BG3 files did nothing. All settings are on their lowest, etc. And it always crashes exactly when I start choosing hair options, it is not by coincidence. It ran fine for many hours yesterday, when I was playing Patch 6. I am at a loss.
So I found, after uninstalling/reinstalling again, files labelled Profile 6 inside the Larian Studio file in appdata/local. After deleting those specifically (instead of the whole file), I was forced to make a new profile, but I finally got past character creation. However, the game did crash a few moments after I started exploring the Nautiloid ship, with the same message about corrupted data afterwards...
