Also having problems with Shareport (SP) after I upgraded my (wireless connected) notebook from Windows 8 to W8.1.
I had problems with SP v4.11 but was using SP v1.20 without problems up to recently (although very occasionally it failed to see a USB device). After upgrading I tried to (re-)install SP v1.2, SP v4.11 as well as SX Virtual Link v3.12, but nothing works, even after turning off the firewall in W8.1.
Is there any work around solution to try? Or is it somekind of setting in Windows 8.1? I use D825 B1 FW2.05EU as a second router in my home network.