Thread:Project:Support desk/Fatal error update to Mediawii 1.23: DatabaseBase::factory no viable database extension found for type 'mysql'/reply (12)

Honestly that is what I expected. ;-) Something must be broken in that PHP installation: Old version number, but version number check not working correctly, the 5.2 install in a folder, where the name makes you think it would be 5.5 and then this strange behaviour; maybe it is also the MediaWiki installation, which is broken. All this is not normal. However, good to know that this behaviour is not reproducable and so - given these circumstances - most likely not a bug in MediaWiki.

Thanks for investigating!