I had issues similar to these and the approach I took was to recreate the datasource and republish to server on top of the problematic one.
If that something feasible for you, give it a try (maybe test first as a new datasource with a different name) and check if the refresh procedure is restored. Then you can replace the one that is used by your dashboards using the same procedure.
I hope this helps
It would be very helpful if you could tell us what are you creating extract of? What sort of database/connection?
I am connecting to Microsoft SQL Server database.
And your own Tableau Server, not Tableau Online, correct? If Online - pm me site name - I'll look into it.
Is MSSQL database hosted on on-prem?
It's not Tableau Online. And yes, the MS SQL is on premises.
Do you have access to "Background Tasks for Extracts" status viz?
If yes - find your refresh there and see if there's a better error message in the tooltip.
No I don't have those access. The message that you see above was the only message that I get.
Actually, my extract refreshes are working absolutely fine now. It was on that day that it failed multiples times. So just wanted to know the possible reason.
Most likely reason is that there was some issue/maintenance on the database side.
Did you check with your DBAs?