can't install unity on mac

I downloaded unity on a Mac 0S Extended (journaled).
When I run the .mpkg file I get this message:
‘Unity’ can’t be installed on this cmputer.
No message found for index 16
any thoughts?

Try the following:

-Make sure your running as Admin
-Make sure your not running it from an external file viewer
-Make sure your system reaches the system requirements
-Make sure its the official one from the Unity3d website (not a pirated one)
-Uninstall all currently installed Unity products

If none of these work then i would have no idea what to do
Have fun troubleshooting ! :)