There seem to be some confusion here.
5.0.7 is the latest version of the Xtreme THEME (not plugin) which is free (no license).
It should be installed or updated directly from WordPress admin using Appearance > Theme, if Xtreme is not installed, or updated Via the Dashboard Update if the theme is installed.
In addition, you should also have installed the free Xtreme Theme Support plugin (v 5.0.1).
What you buy a license for is the Xtreme Plus plugin. The latest version of that plugin is 4.0 and has to be downloaded from your Weaver account, then installed as a plugin.