I have a runbook that has been running fine for a long time. It throws an error suddenly. I am able to refresh the model in SSMS and also works fine when I do a on demand refresh in Azure. The error comes only at time of scheduled refresh.
The thing is Invoke-ProcessAsDatabase is standard cmdlet that I am using in several runbooks but they dont throw any error
Invoke-ProcessASDatabase : The server sent an unrecognizable response. At line:37 char:11 + $result = Invoke-ProcessASDatabase -Server $ServerName -DatabaseName ... + ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + CategoryInfo : InvalidArgument: (Sub Prequal Search:String) [Invoke-ProcessASDatabase], ResponseFormatException + FullyQualifiedErrorId : Microsoft.AnalysisServices.PowerShell.Cmdlets.ProcessASDatabase
We could not reproduce such kind of issue, in your case, try to create a new runbook with the same code and link to a new schedule.