020602060206 Some players have said that simply making a new save allows them to add back their old saves and play them. If that doesn't work for you, try adding back any mods or custom content you were using prior to the patch, updated versions where necessary of course. Some other players who couldn't load their old saves after creating the new one have said that helps.
I'd also be interested in knowing what mods and cc you've been using, as this is a widespread issue and it would be helpful to have lists from affected players to compare.