iafdragonfix

IAF Dragon Den Fix
A lightweight Forge mixin mod that fixes a server/client crash caused by Ice and Fire’s Dragon Dens and Dragon Roosts generating outside the available chunk region.

The Problem
Ice and Fire’s dragon dens and roosts place blocks across a large radius (30+ blocks for caves, 20+ for roosts) during world generation. When these structures generate near the world border or chunk loading boundary, the generation code attempts to access chunks that are not loaded in the WorldGenRegion cache, throwing RuntimeException: We are asking a region for a chunk out of bound and corrupting the save.

How It Works
This mod uses Mixin to intercept two methods in WorldGenRegion:

getBlockState — Returns air instead of crashing when a feature tries to read a block from a chunk outside the region’s cache.
addFreshEntity — Silently cancels entity spawning (e.g. the dragon itself) when the target position is outside the available chunks.
Dragon dens and roosts still generate normally. Only the portions that extend beyond the loaded region are gracefully truncated. No structures are skipped, and normal world generation (trees, ores, etc.) is completely unaffected.

Installation
Drop iafdragonfix-1.0.0.jar into your mods folder.

Requirements
Minecraft 1.20.1
Forge 47+
Compatibility
Tested with Ice and Fire 2.1.13-1.20.1-beta-5
Does not modify Ice and Fire itself — compatible with other IAF addons
Safe to add or remove at any time