[MC-185883] Generating a flat world with the overworld preset crashes

To reproduce:
Go to create a new world,

Select Superflat as world type,

Customise > Overworld

Create the world

Linked issues

Thank you for your report!
However, this issue is a Duplicate of MC-184730.

Please use the search function in the future to prevent duplicate reports.

Quick Links:
📓 Issue Guidelines – 💬 Community Support – 📧 Customer Support – ✍️ Feedback and Suggestions – 📖 Game Wiki