Hi Jakob,
1) Thanks for reporting that issue. I just released an update to the core plugin that fixes that bug.
2) Are you sure the button is actually there? Can you highlight it to reveal it? The CSS in my plugin is definitely making it green, so you must have some CSS on your site that is taking precedence. You can customize the look of that button by applying your own CSS like #bbpress-forums div.bbp-reply-content a.bbp-voting-accept-answer-button {background-color: red;}
Thanks for purchasing the pro plugin. Please let me know if you have any other questions or issues. Thanks.
