HEUREKA!!
I had the same problem like others, couldn't save. After a lot of trying and loading on an other computer (without success) I now have found the conclusion. For some reason the zip doesn't automatically extract the Game folder together with the other dates!
(Look into your folder Gr_1869, if there is no game folder, you shouldn't be able to save)
If that happens to you, just extract the game folder SEPARATELY into the Gr_1869 folder. Then you can plöay ans save. Good luck