Freemius trial notice throws 400 when dismissed

Probably could be fixed by an update to the Freemius framework, but when I dismiss the notice to bump up to the paid version of your plugin, it throws a 400 error and shows up on the next page view:

http://example.com/wp/wp-admin/admin-ajax.php?_fs_blog_admin=true

Form data - action=fs_dismiss_notice_action_wp-fail2ban&message_id=trial_promotion

Let me know if you can’t reproduce.

I’ve seen this once before - are you using Broken Link Checker?

Nope. And it’s either working now or I forget which client site it was throwing the error on. I’ll send along a list of active plugins if/when I catch it again.