BEFORE CONTINUING:

• Always check you are using the latest version of these mods and its dependencies
• Remove known problematic rendering mods such as Optifine, Sodium and others

Version-Loader

1.20.1-forge

Moonlight Lib Version

moonlight-1.20-2.16.15-forge

Issue Detail

Game crashes during tag reload due to a missing block tag:
java.lang.IllegalStateException: Missing tag TagKey[minecraft:block / minecraft:saplings]

The crash happens on the title screen when clicking “Singleplayer” or while reloading tags.
Crash occurs before the world loads (no existing save data involved).
Stacktrace shows Moonlight and Immersive Weathering interaction.

Log Attachment

crash-2025-11-03_13.49.00-client.txt

latest.log

OPTIONAL: To Produce

1. Launch the game with Moonlight, Dynamic Trees and Immersive Weathering active.
2. From the title screen, click “Singleplayer.”
3. Crash occurs during the screen is loading.

OPTIONAL: Which mods are affected?

• Moonlight
• Dynamic Trees
• Immersive Weathering

This is likely an issue form IW. Definitely not from here

Or some mod broke the sapling tag

Thanks, I already submit the issue to IW, by the moment a workaround to solve it is using the mod lmft

Well so that proves it. Sone mod is breaking that sapling tag. That's the actual culprit. You sure that's IW?

IDK which mod is the culprit, but I confirmed just happens when Dynamic Trees BWG-1.20.1-1.0.7 is loaded, I already tried with 2 previous versions but still happening

Well if using dynamic trees alone breaks the saplings tag which can be viewed from the log then this is 100% their issue