### Setup and configuration

- Mermaid version:
- MediaWiki version:
- PHP version:
- Database system (MySQL, PostgresQL, etc.) and version:

### Issue

Produces a [stack trace](https://www.semantic-mediawiki.org/wiki/Help:Identifying_bugs) and outputs:

```
```

Steps to reproduce the observation (recommendation is to use the [sandbox](http://www.sandbox.semantic-mediawiki.org)):