DamageSource Is Not Null: Plus

DamageSource Is Not Null: Plus requires the core protection layer from DSNNULL Basic and expands coverage to many third-party modded entities and custom damage paths. If you are a normal player, server owner, or modpack author, this is the version you probably want.

Project structure

The DSNNULL project is now split into two parts:

DSNNULL Basic

The core module. Provides the shared guard logic, fallback handling, and baseline vanilla-oriented protection.

DSNNULL Plus

The extended module. Builds on Basic and adds extra compatibility coverage for supported third-party mods and modded entities.

This split was made because maintaining both the core system and all modded-entity coverage inside a single package became increasingly difficult. Separating them makes the project easier to maintain, expand, and debug.

Explanation on the DamageSource Null Pointer Exception

Vanilla Minecraft and mod loaders assume that DamageSource is never null.

However, some mods still trigger damage or death logic incorrectly and pass a null DamageSource, which can cause crashes such as:

LivingDeathEvent.getSource() is null

These crashes can interrupt gameplay and create issues that are hard to debug, as the stacktrace seldom includes the actual method that pass a null into damage handling pipeline. This mod provides a defensive layer to prevent such issue from causing crash, and it also catch the point where null is passed into the pipeline, so that the actual debugging could be easier.

Debug tools

This mod includes debugging tools to help locate missing coverage and vulnerable entities.

/dsnnull debug testall

This command performs a heuristic scan across registered living entities and attempts to identify entities that are still vulnerable to null DamageSource.

If some entities fail the scan, please report it on the issue tracker and attach latest.log so coverage can be expanded in future updates.

About 3.0.0 and transformer-based coverage

Since version 3.0.0, DSNNULL Plus uses a transformer-based approach to expand coverage automatically across a much wider range of classes and damage paths.

This significantly improves automatic patch coverage, especially for modded entities that would otherwise require many manual compatibility mixins.

However, because this also increases how broadly the mod interacts with the runtime, it may introduce compatibility risks in very large or complex modpacks.

If you're experiencing a start up crash and removing DSNNULL Plus makes the crash disappear, please submit the full latest.log to the issue tracker so the case can be investigated.

This is especially helpful for identifying unexpected transformer interactions and improving future compatibility.

Limitation

DamageSource Is Not Null: Plus is a defensive mitigation mod, not a guaranteed universal fix.

Because of how modded Minecraft works, it cannot guarantee protection in every possible case.

Some mods may still:

• bypass guarded paths
• override or replace core damage logic
• crash before this mod can intercept the issue
• require case-specific compatibility support that has not yet been added

Environment

• Forge - 1.20.1
• NeoForge - 1.21.1

Support

If you'd like to support my modding work, including maintenance, updates, and compatibility work, Patreon is available here:

https://patreon.com/vomiter_scp