Minecraft world error?

Hi, I once had a Minecraft map and now I accidentally went with LabyMod, and I just end up in a strange map. On the art thumbnail you can still see everything like the sand etc. Does anyone know how to go back to the sand map and so I have it all again? It was a lot of work.

Are you using a different version with Labymod than before?

If so, it could be because…

I once played it without LabyMod, everything went fine when I played LabyMod. Now I can no longer use the other version, so everything is different.

Do you still have a backup?