Azure MCS catalog update fails with FailedToStartImagePreparationVm - CreateUpdateVm-1 timed out

Unable to update a machine catalog for an Azure hosted MCS deployment. The MCS process fails early about 15% into the update The error message shows "Error - Terminated", and the action name is "MCUpdateMachineCatalog" The full stack trace is similar to this : TerminatedStack Trace: at...