Quit the Unity Hub from the icon tray (the thing bottom right) and relaunch the Unity Hub as administrator.
This is apparently an issue with the new hub beta. [Someone shared this solution in the “Share your Unity Hub 3.0 Beta Feedback Here” thread.]( Share your Unity Hub 3.0 Beta Feedback Here page-5#post-7369118)
It worked for me, if it doesn’t work for you close it from the task manager and try opening it as admin again. If the error persists, maybe there’s some hope in the official thread I posted right there!