Problem:
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.

Cause:
An unknown installation problem.

Solution:

1. 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\
   
2. Run Rhino 5.
3. Click Enter a License.
4. Enter your Rhino 5 license.
5. Click OK.