I played Minecraft without any internet connexion during around 3 days. Today I start playing with internet. The launcher updated. When I open my world (I'm not playing on a Realm but my world is saved on my computer), it was just like if some pieces of chunks exchanged places. Some part of my builds was duplicated in other places, parts of some builds just pop into other builds and parts of some builds just disappeared. 

I tried to launch again my world few time, but I had the same problem every time : builds half cut or displaced. 

Do you have any idea of what happened and what I could do to fix this problem ?

Thanks and have a nice day.