I generated a new world and I spawned next to a forest, I turn around and see that some trees generated with coal ore instead of leaves.
Related issues
Attachments
Comments

[media]

Please provide seed and coordinates.

Please also force a crash by pressing F3 C for 10 seconds while in-game and attach the crash report ([minecraft/crash-reports/crash-<DATE>-client.txt|http://hopper.minecraft.net/help/guides/finding-minecraft-data-folder]
) here.