Power BI Server Scheduled Update Failing with Unspecified Error

Hi there,

I am wondering if anyone can help me? I am struggling with A powerBI report which pulls data in from and Access database via import. It works fine in PowerBI Desktop and refreshs correctly. When it is uploaded to PowerBI server it throws the follwing error when attemting to refresh the data:

2018-11-25 01:06:08.5786|ERROR|60|Error Processing Data Model Refresh: SessionId: 5f88c235-56fa-4ae1-85bf-fa34aa0d67be, Status: Error Failed to refresh the model, Exception Microsoft.AnalysisServices.OperationException: Failed to save modifications to the server. Error returned: 'Unspecified error. The exception was raised by the IDbCommand interface.
'.
   at Microsoft.AnalysisServices.Tabular.Model.SaveChanges(SaveOptions saveOptions)
   at Microsoft.PowerBI.ReportServer.AsServer.TOMWrapper.RefreshModel(Database database)
   at Microsoft.PowerBI.ReportServer.AsServer.AnalysisServicesServer.RefreshDatabase(String databaseName, IEnumerable`1 dataSources, String clientSessionId)
   at Microsoft.PowerBI.ReportServer.WebHost.EventHandler.AnalysisServicesDataRefresh.RefreshDatabase(AsDatabaseInfo asDatabaseInfo)
   at Microsoft.PowerBI.ReportServer.WebHost.EventHandler.DataRefreshScope.<>c__DisplayClass9.<ExecuteActionWithLogging>b__7()
   at Microsoft.PowerBI.ReportServer.WebHost.EventHandler.DataRefreshScope.<ExecuteFuncWithLogging>d__3`1.MoveNext()

I have tried connecting the report server to the same data source and it connects fine so I am assuming it is not the OLEDB driver or anything. I have searched on the forum but not found the same unspecified error.

If anyone has any ideas It would be much appreciated.

Thanks.