UE4 landscapes missing along with my games

why have all my landscapes and fillers disappearedafter a free dlc from UE website
So back when i was trying to create my first game n UE 4.10 i had about 8 hours in landscape sculpting work done, looked very nice. I save repeatedly throughout the process saved again after done and got a message to get a free DLC for my engine with new skins i guess you could call them from UE itself mind not a third party I closed out of my project like it said I then downloaded it and merged it into my existing files as its instructiond stated to do my wording may be wrong but yall get the jist anyways i got it all done as instructed then Iwent to re-open my game project and it was completely deleted happened twice and now i have absolutely no skins of any kind at all with either UE4.10 or 4.11