When I create new members their blog theme defaults to the WordPress Default 1.6 by Michael Heilemann. I believe this happens even when that theme is deactivated.
When this theme is used for the members blog, there is no problem because the blog is the home site located at testmember.portalsoup.com and there is no options bar on this theme.
When you go to my blogs for the member in bp, the options bring you to the admins site, blog to portalsoup.com/blog, home to portalsoup.com
I expected the blog button would bring you to blog of who ever is signed in. This is what it is attempting when the member theme is used and is when you get the error.
1. Same results with default themes. Note: default themes did not come with the buddy press plugin when I installed it. I installed the default themes from https://buddypress.org/extend/themes/
BuddyPress Default Home Theme 1.0.1 by Andy Peatling
BuddyPress Default Member Theme 1.0.3 by Andy Peatling