Empty discount code a problem since last update

Ever since I applied the most recent EME update, registrations for a free event (that has the discount field in the admin section empty) have this showing up in the discount column:

Warning: number_format() expects parameter 1 to be double, string given in /home/…/wp-includes/functions.php on line 222

It’s easy enough to ignore the error message in the printable form of the reservation listings, but in the CSV export, the HTML throws off the lines. So it would be nice if we could get a solution to this issue.

Thank you.

https://ww.wp.xz.cn/plugins/events-made-easy/