As I've already say, this is a theme conflict with wpForo. it should only happen with wpForo because wpForo the only plugin which has it's own title/meta-data system on your website. We could check the theme if you send it as a zip file to the same email address. We'll get back within 1-2 days.
I already found the problem is in my topic is wrong this line in the header.php
<title><?php wp_title(); ?> <?php bloginfo( 'name' ); ?></title>
Replaced it by this.
<title><?php wp_title(); ?> and here the description of my web </title>
And leave blank the title in wordpress
And finally the problem was solved.
Very happy.
Thanks for your help.
I have had to modify more codes but I think it's fixed.
Would need to eliminate this blank but I do not know where this the code, but at least the title twice in the forum is no longer visible.
It seems you've added ' ' in Forum Title field. This is a simple space ' ', and you may not see in setting field.
Although I add a "." alone appears the same
I hope that some upgrade solve this problem because it is impossible to fix it, that the forum generates its own title and uses the title of wordpress too.
