Thread:Project:Support desk/1.17, 1.18, 1.19, 1.20, 1.21 Critical bug - lack of translation of page name to suitable encoding - whole site is broken by update scripts (not updated)/reply

You should check first what is the collation of your tables in the database. Look at the  column after issuing a   command in the mysql command prompt on the wiki database (or use phpmyadmin to look at this information).

The recommended collation is "binary", although utf8 should work. If you're using any other collation a conversion may be required.

Did you upgrade from a very old MediaWiki version before 1.17?