Seems like eZ publish cant connect to the database. Check your database settings. Do you have your database settings in <i>settings/override/site.ini.append</i> or <i>settings/siteaccess/my_siteaccess/site.ini.append</i>?
Could you post your HostMatchMapItems from <i>settings/override/site.ini.append</i>?
Check out these threads:
http://ez.no/community/forum/install_configuration/database_would_not_accept_the_connection http://ez.no/community/forum/install_configuration/kernel_error_50
We have put the debug-enable-code in the settings/override/site.ini.append but unfortunately we do not get any debug code. When we switch to MatchOrder=uri we see the debug output
All we get is
kernel (50)
* No database connection could be made, the system might not behave properly.