Version Information

Minecraft: 1.12.2
Forge: 2705
Mantle: 1.3.2.24
Natura: 4.3.2.24

Report Information

When a redwood tree is planted at low Y coordinate and grows, the redwood blocks that generate below the tree will replace bedrock, making it possible for players to remove this wood and fall out of the world. This is a major issue for survival servers.

Steps to Reproduce

Plant saplings at low Y coordinate (on grass/dirt)
Allow the tree to grow through normal means (bonemeal, light)
When the tree is grown, check bedrock below it.
Break wood blocks to find a hole in the world.

Crash Log

Forge Log

This report came from a server tester, I do not have a client log. If needed, I can attempt to replicate the issue myself and provide the necessary log.