> ## Documentation Index
> Fetch the complete documentation index at: https://www.thundercompute.com/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# Troubleshooting

> Troubleshoot common Thunder errors. Find solutions for connection issues, function errors, SSH problems, and access logs. Get support via Discord.

## Common solutions

1. Reconnect to the instance with `ctrl + d` and `tnr connect <instance_id>`
2. Upgrade tnr. Depending on your install method, you may have to use `pip install tnr --upgrade` or re-download the binary from the website
3. Back up any important data, then delete and recreate the instance.

## Common errors

### Function not implemented

A common error you may encounter is some variant of "This function is not implemented." What this means is that your program touches a portion of the CUDA API that we do not currently support. If you encounter this, please contact us.

### MCP / AI agent issues

For MCP server connection, authentication, and remote-VM browser callback issues (Claude Code, Cursor, Codex, etc.), see [MCP Server → Troubleshooting](/docs/guides/mcp-server#troubleshooting).

### SSH errors

If you encounter SSH-related errors (like `Error reading SSH protocol banner` or permission issues), first retry the command.

For quick fixes, back up critical data and recreate the instance. Instances cannot be stopped or restarted.

For persistent SSH issues, see our [SSH on Thunder guide](/docs/console/operations/ssh) for alternative connection methods.

## Recommended Guides

To help prevent common issues and get the most out of Thunder, we recommend these guides:

* [Using Docker](/docs/guides/using-docker-on-thundercompute) - Learn about GPU-enabled containers and troubleshooting Docker issues
* [Using Instance Templates](/docs/guides/using-instance-templates) - Use pre-configured environments to minimize setup issues

## If Compatibility Issues Persist

If you continue to experience compatibility issues or errors that cannot be resolved through the above methods, try resizing the instance or contact support with the failing command and logs.

## Support

The fastest way to get support is to join [our discord](https://discord.com/invite/nwuETS9jJK). Our founding team will personally respond to help you as quickly as possible.


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