Have you tried to update the theme by running the automatic theme updates and you got this error?
“Download failed. Unauthorized”
The issue is in the theme registration and it can be solved quickly. The most common case, causing this issue is: if you registered the theme on a subdomain or a different folder on your server and then migrated the WP site to another domain (URL), leaving the theme registration as is (pointing to your old URL).
The solution is to register the theme again with the same license key. Go to Appearance -> Theme Registration, deactivate the license key and activate it again with the same license key.
That will solve the “unauthorized” error and the theme updates will work normally.
If you get an error, while activating the theme again, stating, that your license key is already in use on another domain (URL), then please check out this help article for further instructions.