After I moving Blender to the 'Applications' directory it works fine. The trouble starts when another user with his/her own account on the Mac wants to run Blender too when logged-in to his/her account. Then it tells you that you don't have the right permissions to open the Application 'Blender'.
I am not new to Linux/Unix permissions and have tried to set the permissions, but even if I set it to world-readable/writable/executable, it still doesn't.
(Mac OS Sierra)