[MC-179829] Game crashes while optimising a previous snapshot world

When you try to optimise a 20w16a world or lower the game closes.

Linked issues

Duplicate of MC-179841

Thank you for your report!
We're actually already tracking this issue in MC-179841, so I've resolved and linked this ticket as a duplicate.

If you would like to add a vote and any extra information to the main ticket it would be appreciated.

If you haven't already, you might like to make use of the search feature to see if the issue has already been mentioned.

Quick Links:
📓 Issue Guidelines – 💬 Community Support – 📧 Customer Support – 📖 Game Wiki