Are you trying to Browse or Direct Connect to them? That is a typical answer. It is not always possible to browse everyone, especially if they do not have the Chat icon beside them. And Direct Connect can be even more difficult. How to use Magnet Links & Direct Connect & check up option of how to show Chat icons. Actually it's easy, right-click column heading bar of search results window & choose Chat from the menu that appears. Do same with download window & also upload windows.