This is KB article provides good debugging information for Content Transfer/Oblisync in general.
CA Business Service Insight 8.3.x and 9.x
1. Make sure that the Content Transfer path is correct in advanced settings
2. You should also go to the Content Transfer/Oblisync URL and make sure that this returns successfully.
The path should be like: http://<machine name>:port/oblisync/api/ObliSyncRepository.svc
3. Via IIS manager, make sure that the IIS port is correct
4. Check the %OG_HOME%\Oblisync\Replicas.xml file and verify the path for local (default) environment