Re: In trying to open a theme i get this code
I ran into this same error message this morning. In case it helps, here’s how it happened to me.
I had MU 2.7 installed on a ubuntu server and MU 2.7 also installed on a local dev installation of ubuntu (both 8.10, if that matters). I upgraded the dev MU to 2.7.1, then installed buddypress. worked great. then I tarred up the dev installation, copied it over to the server, and overwrote the old 2.7 MU non-buddypressed install with the dev files. Ran the upgrade (at http://veryhandso.me/wp-admin/wpmu-upgrade-site.php). Tried to preview the buddypress theme and end up with the error mentioned above.
I then backed up and tried to do a more careful replacement of the files as outlined on the upgrading wordpress page (https://codex.wordpress.org/Upgrading_WordPress). Still no love.
Thanks for any help. Grateful newbie.