u/Amray19

Hello, my friend and I have been building a creative map together, just for personal enjoyment. The past two days we spent a few hours adding more stuff into the world, but today when my friend opened up the map again, our progress was gone. Certain things stayed like floor prefabs but walls, stairs and other prefabs completely disappeared. We tried doing it again and we got the same outcome, all of our progress gone. Any assistance would be much appreciated and I'm happy to answer more questions if needed.