DamageSource Is Not Null Plus

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

❌ No More NPE — LivingDeathEvent.getSource() is null

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

It adds runtime guards to several common damage/death paths so that many invalid DamageSource cases can be caught before they crash the game. It can also log useful information to help identify the offending mod.

Limitation

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

However, due to the nature of modded Minecraft, it cannot guarantee protection in every case. Some mods may bypass the guarded paths, override core methods, or crash earlier than this mod can intercept.

This mod is best understood as a safety layer that reduces crash risk and improves diagnostics — not as a promise that all such crashes are solved.

🆕 Version 2.0.0

Version 2.0.0+ significantly improves the internal safety guard and debugging tools.

Key improvements include:

• 🛠 Improved command tools for testing and diagnosing DamageSource issues
• 🧱 Multiple loopholes closed in the original guard implementation

These changes make the protection more reliable in large modpacks and help modpack authors locate problematic mods more easily.

⚠ Upgrading to 2.0.0 is strongly recommended.

Currently, 2.0.0 is only on 1.20.1 Forge. The improvements introduced in 2.0.0 will be gradually backported to other supported versions (Forge, Fabric, and additional Minecraft versions) over time.

🛡 What This Mod Does

This mod injects safety checks into:

• LivingEntity#hurt
• LivingEntity#die

If a mod incorrectly triggers damage or death with a null DamageSource (which should never happen), this mod will:

• Prevent many common NullPointerException crashes
• Replace the invalid source with a fallback generic DamageSource
• Print detailed logs to help modpack authors locate the culprit

🚨 Why This Exists

While vanilla and NeoForge expect DamageSource to never be null,
some mods still trigger events incorrectly and crash the entire game.

Normally, this results in errors like:

LivingDeathEvent.getSource() is null

Which kills servers and interrupt gameplay for reasons outside the player's control.

This mod acts as a runtime safety net for such situations.

⚠ Important Notes

• ❗ This mod does not fix the broken mod — it only prevents crashes.
• ❗ This mod is a defensive mitigation mod, not a guaranteed universal fix.
• ⚠ If you see warnings in logs, you should still report them to the mod author.
• ✅ Safe to use on both client and dedicated servers.
• 🧩 Designed to be lightweight and compatible with large modpacks.

📦 Modpack Friendly

If you're a modpack author or server owner, this mod can help:

• Prevent unexpected downtime
• Avoid corrupted worlds
• Collect useful crash info without stopping gameplay

Think of it as a circuit breaker for bad damage events.

🧪 Environment

NeoForge

• 1.21.1

Forge

• 1.20.1
• 1.19.2
• 1.18.2

Fabric

• 1.20.1

📜 License

MIT License — free to use in any modpack.