This short blog shows you one of the possible reasons to resolve the error Your data gateway (Power BI- personal) is offline.
You have configured the Power BI Data Gateway from the portal and saying Connection Successful.
Somehow when you Publish the report there is a warning below.
Publishing succeeded, but the published report cannot connect to the data source because we were unable to find a gateway.
When you view the report in the Portal then you get the error:
Your data gateway (Power BI- personal) is offline
In my case, there is nothing to do with Power BI- personal Gateway. It is the all because pointing to the wrong database.
So Microsoft should take care of the misleading message.