checking 'Enable Steam cloud sync for crusader kings2' in library - crusader kings 2 - properties - updates should make it work
You will probably need to start the game once, then the second time the mod should be downloaded and selectable.
I'm looking forward to an update of one of the old cheat mods though.
Did that, still wont work. I'm over it. I suppose, I'll just have to wait until some event editing/mods are shared by the lovely members here or bumble my way through cobbling something together like I have been able to do in the past.