Report does not refresh on schedule

[Anonymous]

Hello,

I have configured an on-prem report server with the Oct 2020 release. I have a report developed using the same release
that pulls data from a sharepoint list, approx 30 rows total, no calculations or metrics. Just a simple dump of three attributes to a table.  The report refreshes in Desktop without issue as well as within the portal. However, if I attempt to schedule it or refresh on demand in the scheduling interface it does not refresh. The message in the ...\Microsoft Power BI Report Server\PBIRS\LogFiles\RSPowerBI log file is:

2020-11-18 08:00:07.7366|ERROR|61|Error Processing Data Model Refresh: SessionId: 66bda523-cb7a-4055-adc0-c0059efeccfa, Status: Error Failed to
refresh the model, Exception Microsoft.AnalysisServices.OperationException: Failed to save modifications to the server.
Error returned: 'COM error: System.Core, Sequence contains no elements.
The current operation was cancelled because another operation in the transaction failed.

I am using a service account to connect to sharepoint and the rights have been verified. As I mentioned it does refresh successfully
using the service account outside of the scheduling interface.

Any suggestions would be appreciated.

Thank you.

Jeff

[Anonymous]

Update - The report does refresh when scheduled despite the error in the log file, it just takes significantly longer (2 secs vs 15 min).  Is the error causing the longer refresh time or is this just inherent with scheduling?  I'm still curious about the error.

Thanks.