https://bugs.winehq.org/show_bug.cgi?id=51086
--- Comment #7 from matt gardotd426@gmail.com --- I will also add that old prefixes created with 6.6 or so will work when being updated to 6.8. The updating window still hangs, but you can kill the process, launch again, and everything works. So something is wrong with 6.7 or 6.8 to where updating prefixes never completes and creating new (64-bit) prefixes fails.
I've bisected a bug in the kernel before, but never wine, but if you guys need help bisecting I can give it a shot. I am familiar with building wine from source so that shouldn't be an issue