While practicing with SharePoint Excel Services and Power Pivot office web apps, when refreshing the data I got an error saying that
“External Data Refresh Failed……”
By checking the error found a solution from TechNet blog. When using Office web apps in SharePoint 2013, Excel files will be viewed in WOPI (Web Application Open Interface) and edited through Office Web Apps. When SharePoint farm is configured to use excel apps, Excel services and power pivot features will depend on the Excel web app server configurations.
Excel web app runs in SharePoint View ode and Office web server view mode. In URL, if see “xlviewer.aspx” it is running on SharePoint Mode. If URL Contains “WopiFrame.aspx”, excel web app is running in “Office Web Apps Server view Mode”. If we use OWA Server view mode, to view the workbooks, Some BI features like Excel Web Access Web part, Refresh ODataConnections web part, View and interact PowerPivot view/data models...
We have to apply suppression setting on the farm to work with slicers and refresh data. So that we can edit the document in browser with Office Web Apps. We can suppress the Office webapps using following PowerShell command,
New-SPWOPISuppressionSetting –Extension “XLSX” -Action “view”