SAP Message RSOS116 - RFC connection to TREX engine is Null; searching or indexing not possible

Diagnosis
RFC connection to TREX engine is Null.

System Response
Search or Indexing is not possible.

Procedure for System Administration
To enter the RFC connection:
Execute transaction RSODADMIN.
In the Administration of BI Metadata Search screen, in RFCDestination, select the appropriate RFC destination.
Choose Execute.