In patched version ...mission loads to ~90% and then ......

[jojimbo]

Originally Posted by calabresi

Not sure if thats allowed, even if is, how could I downgrade from Steam installation, I´m almost sure an updater will not allow to downgrade.

you can tell steam to "not automatically upgrade" its legal.
all you would need to do is drop the contents of the patch
into your core or parts folder. donbt worry give it a try,if it
still doesnt work you didnt lose anything if it does you can play.