Cannot write License file to Unity folder

I am using an Apple Mac Book Pro 15 in Retina display. I am planning to do all my development in it. But the problem I'm having is that I get the error:
Failed to write license file "Library/Application Support/Unity/Unity_lic_ulf" Please verify you have write permission to this file.
I have changed the permissions of the file using chmod, setting owner, group and others to full wrx, which means anybody can write in the Library folder. But the installation program is not able to write the license file.
I'm sure potential users must have found this problem already, so I am hoping somebody can help with the problem.
I am starting with the free subscription, because I want to be sure that I have the development environment right before I start paying for the subscription.

 

What free subscription are you referring to? You can download Unity for free with no subscription https://store.unity.com/download?ref=personal

 

Thank you for being so prompt. I was referring to the personal subscription. I think the problem is in my laptop setup, I am going to enlist the help of Apple Support. If they can not help, I can remove the software from the computer and try the link that you send me.
Thank you very much for your help.

 

I've hit this once before. From memory a fresh install of unity made the problem go away.