Hello. Thank you for contacting the Toolset support.
First of all, based on the debug information you shared I find that you are using the outdated Toolset plugins. We always recommend running your site with the latest stable release plugin version.
*** Please make a FULL BACKUP of your database and website.***
Could you please update ALL Toolset plugins to it's latest officially released version. You can download the latest plugin release from your accounts page:
=> https://toolset.com/account/downloads/
Once you update ALL Toolset plugins to latest version, please try to create a new site key and try to register your site. Please let me know if you reuqire further assistance.
That seemed to resolve the issue, though I think the more likely thing that allowed me to enter in the license key is I was missing the "www" from the website address.