> For the complete documentation index, see [llms.txt](https://cesium.gitbook.io/cesium-docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://cesium.gitbook.io/cesium-docs/support/no-instance-running.md).

# The launcher says no instance running after I open Minecraft

The launcher has not found a running Minecraft process to attach to.

{% hint style="info" %}
The launcher has not found a running Minecraft process to attach to.
{% endhint %}

## Why it happens

The Cesium Launcher does not start Minecraft. It looks for a Minecraft game that is already running and loads Cesium into it. No instance running means it has not found one.

## Check these in order

1. Minecraft is fully open. Wait until you are at the main menu, not the Minecraft launcher, before checking.
2. Minecraft and the Cesium Launcher are running as the same Windows user. If one is running as administrator and the other is not, the launcher may not see the game. Run both the same way.

## Still nothing

Close both Minecraft and the launcher. Start Minecraft first, reach the main menu, then open the launcher and check again. If it still says No instance running, ask in [Discord](https://discord.gg/3QBFFwbbH) and include your Minecraft version and the launcher you started it from.


---

# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.

## Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation by asking a question.

Perform an HTTP GET request on the following URL with the `ask` and `goal` query parameters:

```
GET https://cesium.gitbook.io/cesium-docs/support/no-instance-running.md?ask=<question>&goal=<user_goal>
```

`ask` is the immediate question: it should be specific, self-contained, and written in natural language.
`goal` is what the user is ultimately trying to achieve, the reason they need the answer. Sharing it helps GitBook give you a better, more relevant answer. A goal is most helpful when it describes the outcome the user wants rather than restating the question. For example, with `ask=how do I create an API token`, a goal like `automate deployments from our CI pipeline` lets GitBook tailor the answer to that use case.

The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.