My sister had wordpress installed in your domain and had some errors during update from version 3.5 to 3.5.1. She couldn't login and no one of sites could be accessed.
I backed up wordpress folder and database and tried to fix restoring wordpress instalation, now I can access the main site but I cannot restore sites, during the process I get this message:
Warning: An existing WordPress network was detected.
If I continue the process of installation I get the same inital problem, no sites can be accessed and I can't login anymore.
How can I restore the multisite database in a clean installation of wordpress?