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  This page describes the Data source refused connection DataLens On-premises
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# [DataLens On-premises] Data source refused connection

`ERR.DS_API.DB.SOURCE_CONNECT_ERROR`

Error loading data.

This error means that a connection to the database could not be established.

To fix the error, check the [connection](../../concepts/connection/index.md) settings:

* Make sure the data specified in the connection is correct: **Host name**, **HTTP interface port**, **Username**, and **Password**. If required, check them with your administrator.
* If the specified port only works over HTTP, disable the **HTTPS** connection option.
* If the host list contains only one host, enter all the cluster hosts separated by commas in the **Host name** field.
* If you are connecting to a database that is not a Yandex Cloud resource, follow [this guide](../../concepts/connection/index.md#external-db-connection) to check the setup for correctness on the database side.
* If you are connecting to a database that is a Yandex Cloud resource, in `Select in organization` mode, check that the **DataLens access** option is enabled in the managed database cluster. If in `Specify manually` mode, check that the hosts you are using have public addresses.