In accordance with our WP compatibility guidelines, we’ll be dropping official support for WordPress versions 3.6, 3.7, 3.8, and 3.9 in bbPress 2.6. For more details, see #2902

Edit: bbPress will require WordPress 4.7, see https://bbpress.org/blog/2016/12/bbpress-2-5-12-requires-wordpress-4-7/ (Dec 8th 2016)

#2902