SymptomsInstalling KeyspanUS4A.pkg in Mac OS disables Parallels network drivers. Host-Only Networking and Shared Networking modes are grayed-out in the VM configuration. In Mac OS System Preferences, the Network pane also informs you that the drivers function not properly.
CauseKeyspan driver conflicts with Parallels network drivers.
Change the driver loading order to load "Pvsvnic.kext" first and "KeyspanNHCI-T.kext" last.
Unfortunately it is not quite easy to do this. You can try moving "/System/Library/Extensions/KeyspanNHCI-t.kext" to "/Library/StartupItems/NHCI/" and kextload Keyspan kext from /Library/StartupItems/Parallels/Parallels after Pvsvnic.kext. (open Applications > Utilities > Terminal and execute "sudo kextload <kext file path>".)
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