I have xCache installed on my website and when trying to activate bbPress, I got the error message above.
With xCache enabled, we can't add WP cache groups because the function doesn't exist.
I took out the lines 413-416:
/** Cache *************************************************************/
// Add bbPress to global cache groups
wp_cache_add_global_groups( 'bbpress' );
Afterwards, I was able to successfully activate the plugin. Could you add an if clause to future versions of the line wp_cache_add_global_groups( 'bbpress' );?
