NoArbitraryIncompatibilityFlag

A BepInEx patcher that removes incompatibility restrictions from RtD mods, allowing them to work alongside other popular Valheim mods.

What Does It Do?

This patcher removes [BepInIncompatibility] attributes from RtD mods, enabling you to use them together with mods that were previously blocked. The mods themselves work fine together - this simply removes the restrictions.

Affected RtD Mods:

• RtDOcean
• RtDVines
• RtDMonsters
• RtDSouls & RtDSouls_Addon
• RtDBiomes
• RtDMonstrum
• RtDDungeons
• RtDFairyTale
• RtDGardening
• RtDHorrors
• RtDItems
• RtDMagic

Previously Blocked Mods (Now Compatible):

• CookieMilk.MagicalMounts
• CookieMilk.MajesticChickens
• CookieMilk.BuildPieces
• CookieMilk.CarryMeMaster
• CookieMilk.DiscordControl
• CookieMilk.UltimateServerControl
• Therzie.MonstrumDeepNorth
• Therzie.WarfareFireAndIce
• Therzie.Monstrum
• Therzie.Armory
• Therzie.Wizardry
• Therzie.Warfare
• blacks7ar.MagicPlugin
• blacks7ar.MagicRevamp
• blacks7ar.SeedBed
• blacks7ar.OreMines
• blacks7ar.BowPlugin
• randyknapp.mods.epicloot

Installation

IMPORTANT: This is a PATCHER, not a regular plugin!

1. Download NoArbitraryIncompatibilityFlag.dll
2. Place it in BepInEx/patchers/ folder (NOT plugins!)
3. Launch the game
4. The patcher will automatically process RtD mods on startup

How It Works

The patcher runs during BepInEx's preloader phase (before plugins are loaded) and uses Mono.Cecil to:

1. Remove incompatibility attributes from RtD mod DLLs
2. Modify initialization code to bypass compatibility checks
3. Preserve all mod functionality while removing restrictions

On first launch with a new RtD mod, you'll see something like:

Patching RtD[ModName].dll...
  Removed 19 incompatibility flag(s)
  Rebuilt Awake() with X initialization methods
  Bypassed integrity checks
Successfully patched 1 RtD mod(s). Removed 19 incompatibility flags.

On subsequent launches (if already patched):

Patching RtD[ModName].dll...
All 1 RtD mod(s) already patched.

FAQ

Q: Is this safe?
A: Yes. The patcher only removes compatibility restrictions. The mods function normally, they just don't block other mods anymore.

Q: Will this break my game?
A: No. If you encounter any issues, they would be unrelated to this patcher. You can always remove the patcher to restore original behavior.

Q: Do I need to reinstall after RtD mod updates?
A: No. The patcher runs on every launch and automatically processes any new or updated RtD mods.

Q: Can I upgrade from an older version of this patcher?
A: Yes. Just replace the old DLL with the new one. The patcher will automatically re-process your RtD mods with the latest techniques.

Q: Will this work with old versions of RtD mods?
A: Yes. The patcher adapts to whatever version you have installed.

Q: What if I want to restore the original DLLs?
A: Simply remove this patcher from the patchers folder and reinstall the RtD mods.

Q: How does this handle compatibility checks?
A: The patcher modifies the mod initialization process to skip compatibility verification while preserving all other functionality.

Technical Details

The patcher uses Mono.Cecil to modify RtD mod assemblies:

• Removes [BepInIncompatibility] attributes
• Rebuilds initialization methods to skip compatibility checks
• Handles integrity verification by preserving method structures while modifying execution flow
• All changes are made at the IL bytecode level before BepInEx loads the plugins

Version

1.0.6

Credits

Created to enable mod compatibility and player choice.

License

Free to use, modify, and distribute.

Need a Universal Solution?

If you need to remove incompatibility flags from mods OTHER than RtD mods, there's a universal patcher available:

UniversalIncompatibilityPatcher: https://thunderstore.io/c/valheim/p/IAmOnTheInternetAndNotScared/UniversalIncompatibilityPatcher/

Note: This universal patcher is NOT made by me (IAmOnTheInternetAndItIsScary). The similar username appears to be someone trolling or making a parody. I have no affiliation with that mod. However, if it works for your needs, feel free to use it!

This patcher (NoArbitraryIncompatibilityFlag) is specifically designed for RtD mods and is the original solution.

Changelog

[1.1.2] - 2026-06-18

Changed

• Added support for two newly released RtD mods: RtDLegends and RtDMythics
• Expanded the target list to 15 RtD mods
• Both the GUID detection set and the patched DLL list now cover the new mods

[1.1.1] - 2026-04-06

Changed

• Updated FAQ to address false claims about patcher causing bugs or performance issues
• Clarified that blocked mods work perfectly with RtD mods
• Documentation improvements

[1.1.0] - 2026-04-06

Changed

• Package structure updated for automatic installation with mod managers
• DLL now included in patchers/ folder within the zip file
• Mod managers will now automatically place the patcher in the correct BepInEx/patchers/ directory
• No more manual file moving required when using mod managers

[1.0.9] - 2026-04-06

Changed

• Implemented dual-layer defense combining Cecil IL patching with Harmony runtime patches
• Cecil layer strips incompatibility attributes and neuters detection code before any plugin loads
• Harmony layer provides fallback protection for runtime detection attempts

Technical Details

This version uses a two-layer defense strategy:

Layer 1: Cecil IL Patching (runs before any code loads)

• Strips all [BepInIncompatibility] attributes from RtD mod types
• Neuters the Fail() method by replacing its body with just ret
• Removes throw statements from static constructor integrity checks
• NOPs all Fail() calls in Awake() method

Layer 2: Harmony Runtime Patches (fallback protection)

• Patches PluginInfo.Incompatibilities getter to return empty array
• Patches Dictionary.ContainsKey to hide our GUID
• Patches Assembly.GetName() to return fake name
• Patches AppDomain.GetAssemblies() to filter out our assembly with recursion guard

The Cecil layer handles the heavy lifting by modifying IL before execution. Even if RtD mods add new detection checks, they all ultimately call Fail(), which now does nothing. The Harmony patches remain as a safety net.

All modifications are in-memory only. BepInEx's patcher system loads DLLs into memory, passes them to our Patch() method as AssemblyDefinition objects, we modify the IL, and BepInEx loads the modified version into the CLR. Original DLLs on disk are never touched.

[1.0.8] - 2026-04-06

Changed

• Added runtime detection evasion for RtD mods
• Patcher now hides from all RtD detection mechanisms
• Assembly scanning is cached to prevent performance issues

Technical Details

RtD mods added detection checks in their Awake() method. The patcher uses Harmony to patch .NET runtime methods:

• Dictionary<string, PluginInfo>.ContainsKey returns false when RtD mods check for our GUID
• Assembly.GetName() returns a fake name when RtD mods scan loaded assemblies
• Stack trace analysis identifies RtD mods by their "Soloredis." GUID prefix
• All modifications remain in-memory only

[1.0.7] - 2026-04-04

Changed

• Switched to runtime Harmony patching
• All modifications now happen in-memory only
• Patches PluginInfo.Incompatibilities property getter at runtime

Technical Details

• Uses Harmony to intercept incompatibility checks
• Patches execute in BepInEx preloader Finish phase
• Returns empty incompatibility array for RtD mods

[1.0.6] - 2026-04-04

Changed

• Updated documentation to be strictly informational
• Removed informal language from documentation

[1.0.5] - 2026-04-04

Changed

• Updated patcher to handle integrity verification in RtD mods
• Modified approach to preserve method structures while bypassing compatibility checks

Technical Details

• RtD mods added integrity checks using IL bytecode inspection
• Patcher preserves original method structures to pass integrity verification
• Initialization flow is modified to skip compatibility checks

[1.0.4] - 2026-04-04

Changed

• Updated README with accurate log output examples
• Documentation improvements for clarity

[1.0.3] - 2026-04-04

Changed

• Rewrote detection code removal approach
• Now rebuilds initialization methods instead of patching IL instructions
• Reconstructs clean initialization flow without compatibility checks

Technical Details

• Rebuilds initialization methods to skip compatibility checks
• Clears problematic method bodies to prevent mod disabling
• More robust approach that works regardless of code structure

[1.0.2] - 2026-04-02

Changed

• Updated README to clarify that all RtD mods include compatibility restrictions
• Documentation accuracy improvements

[1.0.1] - 2026-04-02

Changed

• Updated README with additional documentation
• Added FAQ entries about compatibility handling

[1.0.0] - 2026-04-02

Changed

• Initial release
• Removes [BepInIncompatibility] attributes from all RtD mods
• Supports all 13 RtD mods (Ocean, Vines, Monsters, Souls, Biomes, Monstrum, Dungeons, FairyTale, Gardening, Horrors, Items, Magic, Souls_Addon)
• Removes blocks for 19 popular mods
• Automatic patching on game launch

Technical Details

• Patches DLL files using Mono.Cecil
• Works in BepInEx preloader phase
• Only patches when needed