Thread:Project:Support desk/MediaWiki v1.19.1 installation: Compilation failed: support for \P, \p, and \X has not been compiled/reply (13)

Just tried this and it made no difference to me.

I'm on Cent OS, Plesk 11, with PHP 5.3.3. Re-building PHP in this environment isn't an option (I believe) as it's packaged with Plesk.