Error code -2147467259 when scheduled refresh of a dataset

[CoralieM]

Dataset scheduled refresh has started to systematically fail after previously working.

The error message is :
"

Failure details: The last refresh attempt failed because of an internal service error. This is usually a transient issue. If you try again later and still see this message, contact support.

{"error":{"code":"DM_GWPipeline_Gateway_MashupDataAccessError","pbi.error":{"code":"DM_GWPipeline_Gateway_MashupDataAccessError","parameters":{},"details":[{"code":"DM_ErrorDetailNameCode_UnderlyingErrorCode","detail":{"type":1,"value":"-2147467259"}},{"code":"DM_ErrorDetailNameCode_UnderlyingErrorMessage","detail":{"type":1,"value":"<ccon>Désolé... Une erreur s'est produite lors de l'évaluation.</ccon>"}},{"code":"DM_ErrorDetailNameCode_UnderlyingHResult","detail":{"type":1,"value":"-2147467259"}}],"exceptionCulprit":1}}} Table: Loggers.

"

I tried to clear all data source permissions, then refresh and reenter credentials, supress dataset in Power BI service and republish...  I also verified privacy parameters (everything is set to Organizational), verified gateway...

The thing is, it works if I manually refresh the dataset in Power BI services or in power BI desktop, this error is only for scheduled refresh of the dataset. 

The table "Loggers" in the error comes from 2 others tables of the dataset that are merged together. These two other tables are coming from an Oracle database, and there is multiple queries apply on them in Power Query.

Does anyone have insight into what might be causing the issue ?
Thanks.

[kpost · Accepted solution]

Did this start happening out of the blue or only since the most recent time you published?

If it is happening out of the blue, the message "internal service error. This is usually a transient issue."  Might actually be accurate.

Since you CAN manually refresh the dataset from the workspace on app.powerbi.com, that means there's nothing wrong with your tables or your data model or your credentials etc...  Sometimes the issue really is microsoft's fault, and at least to me, this appears to be one of those times.  If it was an issue with the July update or depracated Data Gateway etc, there would be a TON of people having the same problem and posting here about it.

//Mediocre Power BI advice, but it's free//