When you try to map Content Types to OnBase Document Types on a second physical SharePoint server instance, no Document Types are displayed for mapping in the OnBase Configuration screen.
A second instance of the SharePoint server could exist in a scenario where a primary instance of SharePoint exists on a physical server for users on a company intranet and a second instance is set up outside the perimeter network (also known as the DMZ, or demilitarized zone) for use by external users who need to access the same OnBase database.
OnBase does not support multiple physical SharePoint servers for the Content Connector, Archive Services, or Ad-Hoc Scanning integration, because the identity of the SharePoint server is stored in a column within the OnBase database. Configuring these integrations using the OnBase SharePoint Configuration module from a second SharePoint server instance could overwrite the information regarding the primary server and disable the initial integration.