update your system ?
really, that's the easiest and safest and most compatible method.
Just be sure to have Haxchi already installed, or it would be a little harder to do it on 5.5.2 (not impossible).
If you really want to play without update:
did you try launching the game while being offline?
the console doesn't tell you "launch anyway" ?
If you can launch it at all, you might have to try with loadiine, but it has less compatibility.
again, the easiest method is to update.