WP_Widget Error in 4.3

This topic says resolved:
https://ww.wp.xz.cn/support/topic/wp_widget-error-in-43?replies=8

But still having the issue here. After de-activation the error is gone so it’s really your plugin. I’m using it on a WP4.3 multi site installation.

Hope you can fix this soon. Thanks in advance.

https://ww.wp.xz.cn/plugins/wysija-newsletters/