Previously I’ve encountered this error on the Preview build of Orchestrator 2012 R2 and now I’ve encountered in the RTM bits.
This error appears in the following scenario:
You have SQL server to store the Orchestrator DB. In my case it is SQL Cluster. You have one server where you want to deploy all Orchestrator roles.If you use the installation wizard and deploy all Orchestrator roles at once you will not have this error. The Orchestrator web service will work perfectly fine. But using the all in one installation doesn’t give you the flexibility to have different service accounts. So if you deploy with the all in one installation wizard first the management server and the web features the Orchestrator web service works fine. But as soon you start the installation again and deploy the Runbook server role on the same server the web service starts to give request error upon calling it. Apparently when you deploy the Runbook server role on the management server separately something is changed in the Orchestrator database and the web service stops working. Even if you have other servers with the web service they will also start giving the error.
If you are OK of using all Orchestrator roles with one service account just install all roles at once. If you want to use different accounts have a dedicated server for Orchestrator management role and separate servers for Runbook and/or web features roles. As long as you do not install the runbook role on the management server separately your Orchestrator web service will be fine.