DamageSource Is Not Null Plus logo

DamageSource Is Not Null Plus

Mod

by vomiter

An attempt to fix "NullPointerException: LivingDeathEvent.getSource() is null"

Type

Mod

CurseForge Downloads

0

CurseForge ID

1443253

Last Updated

Apr 13, 2026

Description

🧩 DamageSource Is Not Null: Plus

Tired of crashes caused by mods passing a null DamageSource into Minecraft's damage or death pipeline?

DamageSource Is Not Null: Plus is the full compatibility-focused edition of DSNNULL. It 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.

What this mod does

This mod adds runtime guards to common damage and death paths so that many invalid DamageSource cases can be intercepted before they crash the game.

It can:

  • prevent many common NullPointerException crashes caused by invalid or null DamageSource
  • replace invalid sources with a safe fallback source when possible
  • add broader support for modded entities and third-party compatibility cases
  • log useful diagnostic information to help identify the offending mod

Think of it as a runtime safety layer for broken damage events.

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.

Dependency

DSNNULL Plus requires DSNNULL Basic.

Basic provides the core runtime logic. Plus provides the expanded compatibility coverage.

Why this exists

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
  • crash multiplayer servers
  • create hard-to-debug modpack instability
  • in some cases cause world or tick-related issues

This mod does not fix the broken mod itself. Instead, it acts as a defensive safeguard that reduces the impact of these errors at runtime.

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

This mod should be understood as a practical crash-reduction and diagnostics tool, not as a promise that all such crashes are solved.

Important notes

  • This mod does not repair the original broken mod logic.
  • It reduces crash risk by guarding common and supported modded damage paths.
  • Since 3.0.0, broader transformer-based coverage also means broader compatibility surface.
  • It is designed to be lightweight and modpack-friendly, but unusual mod interactions are still possible.
  • It is safe to use on both client and dedicated server.
  • If warnings appear in the log, the underlying mod issue should still be reported.

Environment

Forge

  • 1.20.1

NeoForge

  • 1.21.1

License

MIT License — free to use in any modpack.

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

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Included in Modpacks

External Resources