AimHeart

Hello, A few weeks ago I downloaded Biomes O Plenty and built a house using both Vanilla and the added blocks. I went to log into the single player world and my house has disappeared. All the vanilla blocks are still there but I can now walk through the walls which used to be there (which were made using Biomes O Plenty blocks). However, the rest of the world is completely fine. There is a jacaranda field not to far from the house and all those blocks are fine, including the Biomes O Plenty blocks. I'm still playing on forge. The only thing that changed is that I downloaded the new Minecraft Launcher and I am using that with Forge. Anyone know how to fix it? I really liked the house I built and wanted to build it in a different world. For context it is a survival multiplayer world.