I saw that, but I kinda doubted he really deleted every save, just ones he didn't want.
The only cause I'm aware of for corrupt saves is running out of disk space, and that would indeed corrupt every save from that point on. But regardless it's problably worth doing a full clean reinstall.
If this is Steam: uninstall the game from Steam and move any valued save games elsewhere. Manually delete the CK2 directories from under the Steam AND MyDocuments folders, now reinstall the game via Steam.
If GamersGate: Move valued save games elsewhere, and uninstall the game. Manually delete the CK2 directories from where GG put them and from MyDocuments. Reinstall the game , download 1.05d patch again and apply it.