I haven't changed any settings, but the latest version is forcing users to register or login in order to register. All events are public, the duplicate and event overlap checks are turned off globally (and even at the event level), yet it continues to force users to the login page when they select the Register button. We are losing registrations as a result of this, and the prior 4.1.0 version is now available on your site - only the old 3.3.2 is available, which has compatibility issues with a prior 4+ version install.