[Theme Horse Support Team]

Hi Robert Verkerk,

Yes recently Attitude theme is not 100% compatible. We are thinking to make it compatible soon. As we are busy on some projects so we may take some time to fix it.

To create a bbpress forum with no sidebar, you can create a forum page from pages and add this below shortcodes to support bbpress forum

[bbp-forum-index]

Then at the below of the page. There is an options (right sidebar, left sidebar, full width, no sidebar). You may choose full width radio button. Selecting here will only take an effect to this forum page only.

Hope this may help you
Thank you!