Crash caused by a mod

My modded server crashes on start (mixin errors, missing dependencies, duplicate mods).

The crash report names the mod: remove client-only mods, add missing dependencies, and remove duplicates or wrong-loader mods.

Before you start: The crash report, and the mods folder open in Files.

Step by step

1. Open the newest crash report; find "Mod File", "Suspected mods" or a mixin error naming a mod.
2. Client-only mods (minimaps, shaders, HUDs, Optifine) crash servers: delete them from mods/.
3. "Missing dependency" or "requires": install the named mod and version.
4. Duplicate mods (two versions of one mod) crash: keep only one.
5. Fabric mods cannot run on Forge and the other way round (unless the pack uses a connector).
6. Restart after each change until it starts.
7. Keep a note of each mod you remove so you can add back the ones that were fine.

Check it worked: The server reaches "Done".

Why it happens: Mods must be server-compatible, for the same loader and Minecraft version, and have their dependencies.

If a pack fails out of the box, send support the pack name and crash report.

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