Thanks for the info - It looks like my copies are broken, both clients did update a short while ago but after doing so i'm still getting one of two faults, exactly which one appears varies each time I kick off the client: inforrect information errors for ./wikidb/user..frm (the user table seems to be empty, even after the client update) Spurious "MediaWiki internal error. Exception caught inside exception handler" faults after the client is assigned a job to do and the static HTML dump folder is created. So, i'm now redownloading both the commons and en data from scratch, and will see how it gets on.