We've got a WPMU site running on 3.0.1, set up 9 subsites, so we've got domain.invalid/site1 domain.invalid/site2 etc
Now however when set up the subsite, whilst it appears in the SuperAdmin backend, when you visit the site we get
'Error establishing a database connection'
Going to the domain.invalid/site10/wp-admin
run the repair database and the following info is given
'wp_ _posts: Table 'wpmu.wp_ _posts' doesn't exist
wp_ _comments: Table 'wpmu.wp_ _comments' doesn't exist
wp_ _links: Table 'wpmu.wp_ _links' doesn't exist
wp_ _options: Table 'wpmu.wp_ _options' doesn't exist
wp_ _postmeta: Table 'wpmu.wp_ _postmeta' doesn't exist
wp_ _terms: Table 'wpmu.wp_ _terms' doesn't exist
wp_ _term_taxonomy: Table 'wpmu.wp_ _term_taxonomy' doesn't exist
wp_ _term_relationships: Table 'wpmu.wp_ _term_relationships' doesn't exist
wp_ _commentmeta: Table 'wpmu.wp_ _commentmeta' doesn't exist'
If you click 'visit site' or 'backend' in the superadmin page, it actually shows you the home site page or backend.
I don't think this is related, but we've got domain.invalid/shop as part of the WPMU with the Shopp plugin, updated to 3.0 whilst the plugin was still of an old version. Trying to update the plugin to 1.1RC we now get
'Fatal error: Cannot redeclare shopp() (previously declared in /var/www/vhosts/domain.invalid/httpdocs/wp-content/plugins/shopp/Shopp.php:714) in /var/www/vhosts/domain.invalid/httpdocs/wp-content/plugins/shopp/Shopp.php on line 791'
but that issue has been a problem for a week or two now, dev'ing other parts of the site & this wasn't yet a priority.