# Troubleshooting

> Fixes for Xi's Multiversion UI Lib problems such as a missing Options button, a menu that says it is off, a missing Config button and English-only menus.

URL: https://xichil.dev/wiki/xis-mvui/v1/troubleshooting/ · Updated: 2026-11-06 · Applies to: Fabric, Quilt, Legacy Fabric, Forge, NeoForge, MC 1.7.10 - 26.3

The library writes everything it does to the game log (`logs/latest.log`, or the launcher's log window), on
lines that start with `[Xi's Multiversion UI Lib]`. Most of the fixes below start there.

## Reading the log

Search the log for `Xi's Multiversion UI Lib`. The lines you may find:

| Line contains | Means |
| --- | --- |
| `UI backend … for …` | It started normally. |
| `No UI backend for …` | Your loader and Minecraft version aren't supported by this version of the library. |
| `Minecraft version unknown` | Your Minecraft version is newer than this version of the library knows. |
| `Disabled by -Dxis_mvui.disable=true` | It was turned off on purpose with that Java argument. |
| `ERROR … failed in mod <id>'s menu code` | That mod's menu ran into an error and is off until a restart. |
| `ERROR … the menus of Xi's Multiversion UI Lib are off until the game restarts` | The library couldn't hook into the game; every menu is off. |

Each `ERROR` line is followed by the error's details. Include them when you report a problem.

## There is no menu button in Options

**Cause:** one of these:

- No installed mod has registered a menu. The library adds the button only for mods that use it.
- The wrong jar for your loader or Minecraft version.
- The library doesn't support this Minecraft version yet (`No UI backend` or `Minecraft version unknown` in the
  log).
- The library turned every menu off after an error (an `ERROR` line in the log).
- `-Dxis_mvui.disable=true` is in the game's Java arguments.

**Fix:** check the log first. Use the jar for your loader from [Installation](https://xichil.dev/wiki/xis-mvui/v1/guides/installation/index.md#pick-the-jar),
update the library if your Minecraft version is newer than it supports, and remove `-Dxis_mvui.disable=true` if
you set it. In every case, the mods keep working; only their menus are missing.

## A menu says "This menu stopped after an error"

**Cause:** that mod's menu ran into an error earlier in this session, so the library turned only that menu off.
Its button in the **Mod menus** list is greyed out too.

**Fix:** restart the game. If it happens again, report it to **that mod's** author with the `ERROR` line from
the log, which names the mod. See [When a menu stops working](https://xichil.dev/wiki/xis-mvui/v1/mechanics/menu-errors/index.md).

## The mod list has no Config button for a mod

**Cause:** depends on the loader:

- Fabric and Quilt: Mod Menu isn't installed. The vanilla game has no mod list.
- Forge 1.7.10 to 1.12.2: the mod didn't connect its menu to the mod list.
- Forge 1.13.2: its mod list never enables mods' Config buttons.

**Fix:** use the button on the Options screen, which every mod's menu has.

## A menu is in English although the mod has my language

**Cause:** on Fabric and Quilt without Fabric API, mods' language files aren't loaded, so menus show their
English texts.

**Fix:** install Fabric API.

## The screen shows "Working…" for a long time

**Cause:** the mod is doing something slow in the background, such as reading or writing files. Only that mod's
menu waits; the game keeps running.

**Fix:** wait; the screen ignores input until the work is done. If it never finishes, restart the game and
report it to that mod's author.

## The game won't start and names xis_mvui

**Cause:** a mod that needs the library is installed without it, or with the library jar for another loader.
The loader's error message then names `xis_mvui` as a missing dependency.

**Fix:** install the library jar for your loader ([Installation](https://xichil.dev/wiki/xis-mvui/v1/guides/installation/index.md)).