A Unity ID allows you to buy and/or subscribe to Unity products and services, shop in the Asset Store and participate in the Unity community.
Separate names with a comma.
In windows I also deleted C:\Users\%USERNAME%\AppData\Roaming\UnityHub\downloadedProjectsMetadata.json.
You can also open a terminal window in your 'SDK\tools\bin' folder... and type: sdkmanager "ndk-bundle" "ndk;19.0.5232133" This should download...