Re: Buddypress and Flutter conflicting
I’ve never heard of Flutter. But the link you provided to the Flutter plugin on the WP plugin repo appears to be for the single-user verison of WordPress and not for WPMU. That could be the issue.
Also, if you visit the homepage for the company that created Flutter, there is a link at the bottom to an alpha version for Mu.
I’m changing this to “not a support question” as you are having issues caused by a 3rd-party plugin (and one that is not supposed to work with WPMU at that) and it has nothing to do with BuddyPress not functioning properly. I’m also moving this to the “Third Party Components & Plugins” forum and out of the “How-To and Troubleshooting” forum.