Re: fatal error: members and groups.
I had that but it was because I loaded buddypress as a subfolder
“Move contents of the extracted folder into “wp-content/mu-pluginsâ€. All files should be in the root of “mu-plugins†not in a sub folder. For example, “mu-plugins/bp-core.php†NOT “mu-plugins/buddypress/bp-core.php—
Once I did that it was fine