Category WordPress default widget title display twice at WP 4.2


After updated to WordPress 4.2, my category default widget title displaying twice. I have 4 sites using this widget so i’m pretty sure this is a bug of WordPress.

I tried to find the solution at but it seems no one using this widget.

Could you help me delete one titile? (you can try it on your site or using grant access to take a look one of my site).