Blog not properly installed

Hello,

One of the best blog in my platform : http://blog.enseignons.be/heembeek/

got a "The blog you have requested is not installed properly. Please contact the system administrator."

I can see the blog in my admin, but i can't change anything to that situation. Furthermore, I can't find the tables in the 256 databases ...

Any chance for me to solve this annoying problem ?
1. How can I find the database associated with a blog ? (it might be a table that is corrupted ? )
2. What are your advices ?

Thanks a lot !!