I built my site on drupal 6.14, 6 months ago. It was set up as general language.
I tried to make it to a multilanguage site and uploaded the required modules such as i18n.
I succeeded to make it work and realized that the site default was english. However I wanted to change the site default to Japanese and then add English version.
I checked on google and everywhere I could but did not find any relevant infos.
I decided to install the Japanese version drupal 6.16 on my former drupal 6.14, thinking that it would works in some way.
Unfortunately, not only it didn't work at all but now, I cannot even access to the admin page.
when I try to access to my site , of course it comes an error.

Can somebody advice me on what to do?
I am newby and have absolutely no knowledge of programming. But I am willing to learn.
Any help is welcome.

my site: http://www.ebiz-con.com

Thanks in advance to all.

Nathalie