We leverage Reporting Services subscriptions a lot to deliver reports via email. A problem we run into frequently is when the user who created the subscription loses permission (leaving the company, changing jobs, etc.) then all of the subscriptions they created stop working. This is because they are the Owner of the subscription and SSRS won’t allow the subscription to run when the owner no longer has permission. Here is a quick powershell script you can use to change the owner using the ReportingService2010 web service endpoint.