The bug

When updating a map from Beta 1.3 to 1.12.2, All chests on the map are deleted. An update to update analysis reveals it occurs at 1.8.

How to reproduce

1. Create a world in beta 1.7.3 or earlier
2. Place a chest
3. Place some items in it
4. Load the world into the latest Minecraft version
   → Chest will be deleted

Notes

I did testing and the problem occurs with chests placed in beta 1.7.3 and earlier. Chests placed in later updates seem to continue existing into 1.12.2.

There was an issue made about this before but was closed without resolution as a "duplicate" when the issue it was a duplicate of was a render issue, not a total chest deletion problem.