Several errors occured during data refresh. Please try again later or contact your administrator.

Hi jtech1343 ,
The error you're encountering during data refresh in the Power BI Service is primarily due to invalid credentials for the SQL data source, as indicated in the error message. While the dataset refreshes successfully in Power BI Desktop, the service relies on credentials configured through the on-premises data gateway to connect to your source, and those may be outdated or incorrectly set. 

To resolve this, go to the dataset settings in the Power BI Service, check that the correct gateway is connected and online, and then re-enter or update the data source credentials under the "Data source credentials" section. Additionally, ensure that the source mapping in the gateway matches exactly with what’s used in your Power BI Desktop file. Once the credentials are properly configured, the scheduled and manual refreshes should work without needing to refresh from the desktop each time.