Rhino 5 cannot run and shows an error message about “_mcneel._zoo5”.
This problem happens when Rhino 5 runs for the first time after it's been insatalled.
An unknown installation problem.
Delete the *.lic file under: For Windows Vista/7/8
C:\ProgramData\McNeel\Rhinoceros\5.0\License Manager\Licenses\ For Windows XP
C:\Documents and Settings\All Users\Application Data\McNeel\Rhinoceros\5.0\License Manager\Licenses\