A tiny server-side library that fixes dedicated-server crashes caused by Sinytra Connector not removing client-only members from Fabric mixin classes.
Just drop it in your server's mods/ folder next to Connector — the crash is gone.
It does nothing on clients, so it's safe to ship in the same pack.
If a Fabric mod loaded through Connector has a mixin with a client-only method, your dedicated server crashes during startup with something like:
MixinPreProcessorException: Attach error for .mixins.json:SomeMixin
-> INVOKESTATIC net/minecraft/client/Minecraft::getInstance
Caused by: java.lang.ClassNotFoundException: net.minecraft.client.MinecraftNote the key detail: no crash report is generated (it dies during class loading), so all you get is this stack trace in the console — which is exactly what this mod prevents.
Connector correctly strips Fabric @Environment(CLIENT) members from regular classes, but it
skips this step for mixin classes. A common mixin carrying a client-only method (correctly
annotated by the mod author) therefore survives on the server, and the mixin processor later tries
to resolve a net.minecraft.client.* class that doesn't exist server-side → crash.
This is a Connector limitation, not a bug in the affected mod — the mod works fine in singleplayer and on native Fabric servers.
Runs just before the mixin processor reads each mixin class and removes any @Mixin member marked
@Environment(CLIENT) on a dedicated server, exactly like the Fabric loader does natively. It's
generic — it fixes every Fabric mod hitting this pattern, not one specific mod.
You'll see this line on server startup confirming it's active:
[ConnectorEnvStrip/]: Registered 'connector_env_strip' launch pluginℹ️ This is a low-level library, so it does not appear in the in-game mod list. Check the startup log line above to confirm it loaded.
