Unity Editor Skin Greyed Out for Unity Plus

I have subscribed to unity Plus, however the editor skin option remains greyed out in preferences.

How do I change the editor skin to dark?

I am using Unity on Mac OS Sierra and am signed into my account.

well, it was really simple in my case. you need to use the serial key they sent via email. it’s not automatic, even though your seat might be shown as assigned to yourself.

Hi, sure you have all sorted it out by now, but just in case anyone else is having this problem, here’s what I did.

In the Unity Hub, I revoked my license and then activated with the serial from the Unity website.