Unable to activate or add my license

If you go to click on the "add license" button after typing in the license key from the email and experience; "the box flashes and erases what I typed, and then nothing happens."

You are likely having an issues due to SketchUp using IE (Internet Explorer) to display the plugin's dialog windows.

Please update your Internet Explorer installation to ensure you have version 11.

It is also possible that Javascript is disabled for IE.  You can fix this issue by following the steps on this site.

Even if Internet Explorer is not your default web browser, you still need to follow the steps.