# Troubleshooting

This page aggregates the most common issues users run into when operating ENSRainbow.

## Common Startup Errors

### "Database schema mismatch"

- **Cause**: Your on-disk database was created with a newer/older schema than this binary understands.
- **Fix**: Upgrade ENSRainbow to the latest version _or_ download a matching database archive.

### "Label set id mismatch"

- **Cause**: You attempted to ingest a `.ensrainbow` file whose `LABEL_SET_ID` differs from the database.
- **Fix**: Create a fresh data directory or ensure you ingest files that share the same label-set id.

### Port already in use

Check that no other service is bound to `3223` (the default port). You can change the port via the `PORT` environment variable as documented in [Configuration](/docs/services/ensrainbow/usage/configuration/).

For frequently asked questions about ENSRainbow, please see the [FAQ page](/docs/services/ensrainbow/faq/).