Minecraft v1.14.4
Forge v28.2.0
Lost Cities v2.0.28

I got this crash after clicking the customize button. First I had selected the rare cities option, then clicked done, then went back into the Lost Cities configuration screen to customize it, but crashed instead. Its strange since this is the first time getting this crash, even though I've used this option before. It might be related to the order I clicked on the buttons.
Crash Report