As of this morning, there appears to be an issue with the API function has_membership(). I thought it was my custom code, but after I resolved the errors from my code, I'm getting errors code I haven't edited.
Specifically in eab-events-membership2-integration.php (plugins/events-and-bookings/lib/plugins). The error says "Call to a member function has_membership() on boolean"
There are three instances of the function in that file, and they're all called on the object $user.
I encounter the error when trying to load an event page in the Admin. The page fails to load the RSVP section properly (because this is where the code which calls has_membership() is located).