> ## Documentation Index
> Fetch the complete documentation index at: https://blogloom.changlu.cloud/llms.txt
> Use this file to discover all available pages before exploring further.

# Troubleshooting

> Diagnose common issues by symptom.

## Backend will not start

1. Check the exception stack in the startup log.
2. Verify MySQL is reachable.
3. Confirm configuration is complete and secrets are set.
4. Confirm port `8090` is free.

## Blank frontend or 404 API calls

1. Confirm the backend is running.
2. Check `VITE_API_URL` in `.env.production`.
3. Check the Nginx reverse proxy and route fallback.

## Login state issues

1. Check that the database connection and the `cache_entry` cache table are healthy.
2. Confirm `token.secretKey` is unchanged.
3. Clear browser storage and try again.

## Content does not update

1. Confirm the database has been updated.
2. Clear the cache and refresh.
3. Check browser and CDN caches.

## Image upload fails

1. Check the image hosting configuration and credentials.
2. Check upload directory permissions and disk space.
3. Look for upload exceptions in the backend log.

## Collect information

Prefer to collect the backend log, browser console, API responses and database state first.

## Next steps

* [Operations](/v1/en/deploy/operations)
* [FAQ](/v1/en/guide/reference/faq)