Installing Preview backend on a server without a Web Application
Certain SharePoint topologies may require that the Preview back-end (Gatherer and Conversion services) must be installed on a SharePoint server which does not have a Web Application – or a server to which for any reason the Ontolica Preview SharePoint solution cannot be deployed. As the Preview backend installer checks, if the solution is deployed on the given server, it will not allow proceeding with the installation in the mentioned scenario.
To resolve the issue you can manually copy the SurfRay.Core.dll and SurfRay.Core.SP[2007|2010].dll into the GAC of the affected server. The dll files can be found on the servers to which the Ontolica Preview SharePoint solution has been already deployed.