I am currently working on Wordpress version 4.8.2 (running on my local PC via wamp) and i have installed a pluging BuddyPress but when i try to activate the plugin, following error occurs :
Fatal error: Call to undefined function dbDelta() in C:\wamp64\www\wordpress\wp-content\plugins\buddypress\bp-core\admin\bp-core-admin-schema.php on line 159
It's better to ask such questions on BuddyPress support forums.
In general, I think, that the issue is not in the plugin, but in the used theme instead. Please try to switch to 2017/2016/2015 theme for a moment, activate BuddyPress on that default 100% supported theme, and then feel free to switch back to NRGNetwork. During the plugin activation it does a bunch of initial things, including DB setup, and it seems it conflicts with what is done in a theme.