This is due to modified version of bespin-service-1.6.0.jar file. Which is trying to invoke wrong API call that is not returning expected result.
Use the default version of bespin-service jar (That has with default installation).
*) Stop the VSCatalog service
*) Take backup of existing bespin-service-1.6.0.jar file (Move this file out side of installation path i.e <VSCatalog_home>/lib).
*) Download attached bespin-service-1.6.0.jar and place it in <VSCatalog_home>/lib
*) Start the VSCatalog service
*) Access VSCatalog portal and go to managed catalog settings. Delete existing ED connection URL and verify the list from virtual service. Make sure that count has reduced.
*) Add deleted ED connection details back from managed catalog setting. And refresh the virtual services list and verify the issue.