I am a long-time Radmin user and have not had this issue before.  I have a new laptop (HP Probook /win10)  I have loaded Radmin  Viewer.  When I connect to Radmin Server on a computer that is on our LAN and same subnet it works fine for almost a minute--then the session just closes.  I have tried this numerous times and it always acts the same.  When I Radmin into the same server with any other machine on the Network I get a perfect connection that doesn't quit.  Even a Mac running Radmin Viewer under Parallels works perfectly.  I gotta fix this.  HP Laptop runs all other software perfectly and without any network problems.    nmskies