Data source credentials greyed out after taking over the dataset

If your colleague is unable to edit the data source credentials for the dataset in the Power BI service, even after taking ownership of the dataset and having admin rights, it is possible that the data source is configured to use a gateway and the gateway settings are preventing your colleague from making changes.

To resolve this issue, you can try the following steps:

1. Check the gateway settings: In the Power BI service, go to the "Manage gateways" page and check the settings for the gateway that is being used for the dataset. Make sure that your colleague has been added as an administrator for the gateway and that the data source credentials are configured correctly.

2. Check the dataset settings: In the Power BI service, go to the "Datasets" page and click on the dataset that is causing the issue. Click on the "Settings" icon and then click on "Security" to check if your colleague has been added as a member of the dataset. Also, check if the "Prevent others from changing the data source credentials" option is enabled, and if so, disable it.

3. Check the data source permissions: Make sure that your colleague has the necessary permissions to access the data source. For example, if the data source is a SQL Server database, make sure that your colleague has been granted the appropriate permissions to access the database and modify the credentials.

4. Try refreshing the data in Power BI Desktop: If your colleague is still unable to edit the data source credentials in the Power BI service, you can try opening the dataset in Power BI Desktop and refreshing the data there. After refreshing the data, save the changes and publish the updated dataset to the Power BI service. This may help to resolve any issues with the data source credentials.