Create content view version fails with Error 500

I can no longer create new versions of content views, in the UI I get a pop up saying “500 Internal Server Error”

Expected outcome:
A new content view version is created.

Foreman and Proxy versions:

  • foreman-2.1.4-1.el7.noarch
  • katello-3.16.2-1.el7.noarch

Distribution and version:
CentOS Linux release 7.9.2009 (Core)

Other relevant data:
production.log: 2021-02-27T14:25:58 [I|app|3416b4df] Started GET "/notification_recipients" for -