bbPress causes white screen on website

If you’ve tried to install bbPress and buddyPress on the same website, possibly experimenting with forum alternatives, you may run into some strange behavior. This can occur even if one of the plugins is deactivated or uninstalled. The strangest I saw as the website being completely blank—a white screen. The admin console worked fine, but the website proper did not, and even though display_errors in php.ini was set to “On,” no error messages were displaying. Just a white screen. If I deactivated the bbPress plugin, the problem disappeared.

Apparently bbPress 2.0 can have some conflicts with buddyPress. Uninstalling the plugin isn’t enough; a lot of database fields are left behind from one plugin, and some of those can confuse the other.

Go into phpMyAdmin, once you have deactivated both plugins. You’ll see many database tables for buddypress, which can be deleted–but that isn’t enough. The wp_options table is filled with rows for BuddyPress and bbPress. You can go through the table manually, checking off rows and deleting them, or run a custom query, like these:
DELETE FROM `wp_options` WHERE `option_name` LIKE '_bbp%'
DELETE FROM `wp_options` WHERE `option_name` LIKE 'bp-%'

Warning! delete items from your database at your own risk. Make sure that you could live with ruining your WordPress install accidentally—either being willing to start over from scratch (as with a test site), or that you have backups and know how to restore from them.

After you’re removed the obvious leftovers from bbPress and buddyPress, there are still two fields in wp_options… innocuously named “template_root” and “style_root” or “stylesheet_root”. These sounded suspiciously like system options, so I was hesitant about removing them, but they both contained BuddyPress data. Once I removed them, I could reactivate bbPress and the site started working again!

Once again, be careful! If you aren’t comfortable with databases, or confident in your ability to replace/restore your website, do not delete any data from your website. Backup your database–or better yet, your entire website–before you do this. Of course, if you make a practice of regular backups, you may choose to restore from a backup before BuddyPress and bbPress instead of manually making alterations to the database.