Форуми / Cotonti / Support / 'page_html' SQL error during upgrade

I upgraded from seditio 12x to 125 by starting this file "mydomain/upgrade-seditio12x-to-seditio125.php". All steps were succesfull it told me in nice green letters.

[edit]
After some more new database imports (I just imported my parts again) I got a step futher. Now I get this error:

Warning: mb_internal_encoding() [function.mb-internal-encoding]: Unknown encoding "windows-1250" in /home/armaholi/public_html/testers/armaholictest/system/common.php on line 44

I did try to create a mutiple language site a while back and guess it can not read that encoding. Will have to go back to the beginning to reset to utf8 too in the admin panel I guess :(
Ahh well, at least like this I will learn all steps from my head :)