Mansion couldn't generate completely

Please provide seed and coordinates.

In which version did you create the world before opening in 18w21b?

Tryed use F3 + A?

My seed is Wisconsin(1900638999), I created my world in 18W16a, and this is my first time to go to mansion (x: 4448, z:-3360)

F3+A couldn't work

Confirmed, see screenshot.

Minecraft hangs when teleporting to that location.

Fixed in 1.13-pre7. Created a world in 18w16a and teleported to a correctly generated mansion in 1.13-pre7.

Resolving as fixed. If someone can still reproduce, the ticket will be reopened.