critical

Two mods refuse to run together

Q: What does "Mod 'Iris' (iris) 1.7.0 is incompatible with any version of mod 'OptiFabric' (optifabric)" mean?

Two mods refuse to run together. The mod loader stopped because two installed mods declare each other incompatible. Remove one of the two mods named by the loader.

Applies to Fabric, Quilt.

What it looks like in your log

Mod 'Iris' (iris) 1.7.0 is incompatible with any version of mod 'OptiFabric' (optifabric)

What causes it

The mod loader stopped because two installed mods declare each other incompatible.

How to fix it

Remove one of the two mods named by the loader.

Not sure this is your problem? Paste your log and Roastd will tell you which of these it actually matched, and what else it found.

Check your own log

Errors that travel with this one

A mod is registering content at the wrong momentjava.lang.IllegalStateException: Registry is already frozen
A mod is patching code that does not exist hereCritical injection failure: @Inject annotation on onRender could not find any targets matching
A Fabric mod is failing inside ConnectorFabric Mod Discovery Failed!
Two mods ship the same library and collidejava.lang.module.ResolutionException: Modules kotlin.stdlib and kotlinforforge export package kotlin to module
Two mods clash inside this packMixinApplyError: Mixin [create.mixins.json:LevelRendererMixin] from phase [DEFAULT] in config [create.mixins.json] FAILED during APPLY
A mod is calling game code that movedjava.lang.NoSuchMethodError: 'void net.minecraft.world.entity.Entity.setPos(double, double, double)'