1. This issue is already fixed, we will release new version very soon.
2.
and I also have to change the background:
Do You want to change background color of "Комментаторы" title?
In this case, please navigate to Dashboard > Comments > Settings > Addons > Widgets admin page.
Add this code in "Widget custom CSS" area:
.wpdiscuz-widgets-content > widget-title > span{
background-color: #color;
}