I was playing Minecraft and it was on the new 1.8 update, and I was on a single-player world. After about 20 minutes, I wanted to play multi-player, but the server I wanted to play was not compatible with the update yet so I put my account back to 1.7.4 and played for a bit. I then went back to the single-player world but the picture frames and item frames had fallen of the wall. My inventory was also empty along with my armor. I thought I put the stuff in my chest so I go to open the chest. But when I did, it was empty. They were all empty. also my dogs where in a different room, sitting, and untamed. Some signs had some words replaced with "null" or random letters. I thought that maybe it was because of the update and it was just a small glitch and my items would be restored after I updated again, but no, I updated and it was all still gone. Every chest empty, every picture fallen, and every item frame empty and fallen. All of my stuff was completely gone. I was wondering if you guys have heard something similar happen to another person or if there was a way to fix it. I also thought you should know just for a bug fix update. Thank you for listening.