"Duplicate search results were found. They were not added to the results list" when trying to use Client Push install of SEP

Where can I find additional information on this message? Why does it come up? What is causing it?

So far we have been able to find target endpoints by using the Search Network option during Client Push and complete the SEP client install. But we would like to know more about this error and what is causing it. We are using SEP 14.x and groups in SEPM are from AD as we are using Directory Server sync.

Thx.