The plugin is version 1.74 and depending on all the options you have for the Thrive Plugins the version of only the Content Builder is 1.2.003. See here for the changelog http://changelog.thrivethemes.com/2016/03/
After updating to the latest version I needed to register the plugin, which will not work for obvious reason if you got it from here. So here is what I did:
1: Update this plugin to 1.2.003
2: Fire up your FTP program
3: Navigate to your WP install -> wp-content -> plugins
4: Find the directory (folder) “thrive-visual-editor”
5: Open this dir and navigate to: thrive-dashboard -> classes -> Product -> LicenseManager.php
6: Download and open LicenseManager.php in your favorite code editor
7: Find line 126 ( it reads: return false;
8: Change return false; to return true;
9: Hit save
10 reupload LicenseManager.php in its original location on the server
11: Reload your browser tab with your WP site
Now you can use the plugin as intended by its author.
Good luck and I hope it helps.