I went to play a house that I started yesterday and things looked strange..I then realized that the rooms were swapped and different things were added/removed from it. I am the only one who plays so I'm confused...any ideas?? Also, I'm not able to acess build mode suddenly...
For troubleshooting purposes:
Are you on Console. PC or Mac? Do you have mods or custom content /CC in your game?
Things in your game should not change on their own. I have a couple of suggestions as to what may have happened.
If the lot was back to the way they were before you quit the game may not have been properly saved.
A good practice is to use the option to "save as" first then quit. The option to "save and quit" (one action) could be an issue.