Thread:Project:Support desk/ Unsupported operand types/reply

Just a guess: You haven't set $wgCacheDirectory to true in your LocalSettings.php and haven't set $wgLocalisationCacheConf, too? In this case, mediawiki's interface messages are saved to the database.

Now another guess: Maybe (i don't know, sorry) the database schema (or the values stored in the same schema) changed from 1.19 to 1.24, so your new install saves some data, which can't be handled by MW 1.19 anymore. It's never a good idea to have one database for several wikis with different versions (in case you haven't different prefixes). I suggest you rollback to your backup and setup MediaWiki 1.24 to a new copy of your database, run the installer to update the database schema and use the new wiki from now :)

Remember that MediaWiki 1.24 is already outdated. The newest MediaWiki version is 1.24.2 and can be downloaded from here.