> ## Documentation Index
> Fetch the complete documentation index at: https://private-7c7dfe99-sync-clickhouse-operator-docs-7e82242.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Breaking Changes

### `helm/onprem-clickhouse-cluster` version `1.1.210`

Starting with chart version `1.1.210`, new config constraints are included by default. If you are using a ClickHouse server version **lower than 25.10**, you must exclude these constraints by adding the following to your server configuration:

```yaml theme={null}
server:
  excludeConfigConstraints:
    - allow_experimental_qbit_type
    - rewrite_in_to_join
    - allow_experimental_alias_table_engine
```

Without this configuration, ClickHouse will fail to start as these settings are not recognized by versions prior to 25.10.