> ## 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.

# FAQ

> Common questions about deployment and usage.

## The backend fails to start with a database connection error

Check the MySQL host, user and password in `application-dev.properties`, and confirm the database was created and the incremental SQL has been applied.

## The frontend reports API errors after startup

Confirm the backend is running on port `8090`, and check that `VITE_API_URL` in `.env.development` points to the correct backend.

## Login says the account or password is wrong

The default account is `admin` / `123456`. If the password was changed, use the new one; if forgotten, reset it through the database.

## Page content does not update

Rendering may depend on both database site settings and the cache. After changing seed data, sync the database and clear caches as needed.

## Images cannot be uploaded

Check the image hosting configuration, and verify the local upload directory or Aliyun OSS credentials and permissions.

## No email notification for comments

Confirm the mail service is configured correctly and check the authorization code and sender settings.

## How do I upgrade the database?

For a fresh environment, run `bin/local/upgrate-sql.sh` to apply all incremental scripts (the baseline includes the schema); for an existing one, rerun it to apply only the scripts not yet recorded in `sql/local/`.

## Next steps

* [Troubleshooting](/v1/en/deploy/troubleshooting)
* [Configuration](/v1/en/deploy/configuration)