[Mediawiki-l] I can't upgrade from MW 1.12.0 to MW 1.16.1

[coet cawiki]

Hi,

I have a problem with upgrading my MW. I think that installation process
can't upgrade shcema for existing tables.

The returned error is really generical:
Internal Server Error

The server encountered an internal error or misconfiguration and was unable
to complete your request.

Please contact the server administrator, webmaster at viquibalear.com and
inform them of the time the error occurred, and anything you might have done
that may have caused the error.

More information about this error may be available in the server error log.

Additionally, a 404 Not Found error was encountered while trying to use an
ErrorDocument to handle the request.


Does somebody know how I can proceed?


Thank in advance.