Error : Problem With SSL CA Cert(Path?accessRights?)

Please try the manual activation flow by disconnecting your internet connection before launching Unity.

You can activate manually through Help/Manage License.../Manual Activation

Hi, I had the same problem, but you have to go on internet to request the license from unity 3d, here https://license.unity3d.com Then when i tried to import packages to new projects, it always said : "unable to decompress package". I read on some other forum, you have to move unity on your C: disc, and it worked. I hope i helped someone :)