> ## 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 Compute 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. Check our [Development vs Production](/development-vs-production) guide for supported features, and 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](/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 Compute guide](/cli/operations/ssh) for alternative connection methods.

## Recommended Guides

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

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

## Production mode as a last resort

If you continue to experience compatibility issues or errors that cannot be resolved through the above methods, consider switching to production mode by modifying your instance ([VS Code](/vscode/operations/modifying-instances), [CLI](/cli/operations/modifying-instances), or [Console](/console/operations/modifying-instances)). Production mode provides maximum stability and reliability with all low-level optimizations disabled, ensuring complete compatibility for workloads that encounter persistent issues in the development tier.

## 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.