Curious if you tried disabling the Windows firewall, even temporarilly to see if that was affecting anything? Jim On Fri, Apr 27, 2018, 10:45 PM Allen Mulvey, wrote: > For the past four years I have been using an rfid/keypad (Wiegand) access > system for my home. Several weeks ago I noticed that my desktop computer > (Windows 10 Pro) which hosts the icCard program to control the system cou= ld > no longer connect with the controller board. I installed the software on = a > relatively clean laptop, also Windows 10 Pro, and had the same results. T= he > software installs and appears to run fine but any attempts to access the > controller board produce a "comm failure" error. > > I installed the same software on a Windows 8.1 VM running on a Windows > 2012r2 Hyper-V server and everything works fine from there. Apparently > something happened to Windows 10 to make it block this sort of > communication. I think it uses UDP but I have not attempted to analyze th= e > traffic. > > Does anyone have any idea what is going on here? I would really like to > get back to managing this system from my normal workstation. > > Thanks, > Allen > > > -- > http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist > --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .