Scheduled refresh and Manual refresh Error

Hi Saldy123​ 

Business Central is closing connection mid refresh usually from throttling or timeouts on large tables. So you can start by checking admin center and Microsoft 365 service health for an outage then reduce load by filtering rows early in Power Query then removing unused columns and tables and avoiding unwanted heavy tables refreshing at once. Re enter your credentials under dataset's settings - Data source credentials and if you use a gateway then update it to latest version. Test refresh in Power BI Desktop so if it fails there too then the problem is in query or business central, and if it works then it's the service or gateway. If it keeps failing you can raise a Microsoft support ticket with the Activity ID and Request ID from error - https://support.fabric.microsoft.com/